diff --git a/.github/goreleaser.yml b/.github/goreleaser.yml
index 6c0ae33e8..c36fae2d4 100644
--- a/.github/goreleaser.yml
+++ b/.github/goreleaser.yml
@@ -77,8 +77,10 @@ release:
     name: silo
   draft: true
   prerelease: false
-  mode: append
+  replace_existing_draft: true
   replace_existing_artifacts: false
+  mode: replace
+  # Draft replacement matches the release name; keep it identical to the tag.
   name_template: "{{ .Tag }}"
 
 changelog:
diff --git a/.github/workflows/finalize-release.yml b/.github/workflows/finalize-release.yml
index 92f63d558..5f4950ed3 100644
--- a/.github/workflows/finalize-release.yml
+++ b/.github/workflows/finalize-release.yml
@@ -23,7 +23,7 @@ permissions:
   artifact-metadata: write
 
 concurrency:
-  group: finalize-release
+  group: release-${{ inputs.tag }}
   cancel-in-progress: false
 
 jobs:
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index c4b9aaae0..e3350283a 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -1,5 +1,10 @@
 name: Release
 
+# Retry contract: an absent or single unfinalized Draft may be rebuilt from
+# scratch; a published release or a Draft carrying finalize's GPG-derived
+# provenance marker is terminal for this lane. The per-tag lock serializes
+# workflows, but a maintainer must not publish the Draft while this job runs.
+
 on:
   push:
     tags:
@@ -16,6 +21,10 @@ permissions:
   attestations: write
   artifact-metadata: write
 
+concurrency:
+  group: release-${{ github.event_name == 'workflow_dispatch' && inputs.tag || github.ref_name }}
+  cancel-in-progress: false
+
 jobs:
   release:
     runs-on: ubuntu-latest
@@ -78,6 +87,15 @@ jobs:
             echo "Invalid release tag format: ${TAG}" >&2
             exit 1
           fi
+          if ! TAG_COMMIT="$(git rev-parse "${TAG}^{commit}" 2>/dev/null)"; then
+            echo "Release tag ${TAG} does not resolve to a commit" >&2
+            exit 1
+          fi
+          HEAD_COMMIT="$(git rev-parse HEAD)"
+          if [ "${TAG_COMMIT}" != "${HEAD_COMMIT}" ]; then
+            echo "Release tag ${TAG} resolves to ${TAG_COMMIT}, checkout is ${HEAD_COMMIT}" >&2
+            exit 1
+          fi
           VERSION_HYPHEN="${TAG#RELEASE.}"
           PKG_VERSION="$(echo "${VERSION_HYPHEN}" | sed -E 's/^([0-9]{4})-([0-9]{2})-([0-9]{2})T([0-9]{2})-([0-9]{2})-([0-9]{2})Z$/\1\2\3\4\5\6.0.0/')"
           VERSION_COLON="$(echo "${VERSION_HYPHEN}" | sed -E 's/T([0-9]{2})-([0-9]{2})-([0-9]{2})Z$/T\1:\2:\3Z/')"
@@ -93,6 +111,13 @@ jobs:
           echo "Package version: ${PKG_VERSION}"
           echo "LDFLAGS: ${LDFLAGS}"
 
+      - name: Check existing release state
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          buildscripts/check-release-state.sh "${RELEASE_TAG}"
+
       # Both installer actions are pinned to immutable commits. The explicit
       # tool versions keep the release format reproducible across workflow
       # reruns while the installers verify the downloaded executables.
@@ -113,6 +138,7 @@ jobs:
           args: release --clean --skip=validate --config .github/goreleaser.yml
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GORELEASER_CURRENT_TAG: ${{ env.RELEASE_TAG }}
           LDFLAGS: ${{ env.LDFLAGS }}
           PKG_VERSION: ${{ env.PKG_VERSION }}
 
@@ -189,6 +215,14 @@ jobs:
           test -s "${BUNDLE_PATH}"
           cp "${BUNDLE_PATH}" "dist/silo_${PKG_VERSION}_provenance.sigstore.json"
 
+      - name: Confirm unfinalized Draft release state
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          REQUIRE_DRAFT: "true"
+        run: |
+          set -euo pipefail
+          buildscripts/check-release-state.sh "${RELEASE_TAG}"
+
       - name: Upload nFPM packages to Draft release
         env:
           GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/test-release.yml b/.github/workflows/test-release.yml
index e717fcde6..2ab3c2ad3 100644
--- a/.github/workflows/test-release.yml
+++ b/.github/workflows/test-release.yml
@@ -23,6 +23,8 @@ on:
       - "buildscripts/minio-upgrade.sh"
       - "buildscripts/sign-release-rpms.sh"
       - "buildscripts/verify-build-provenance.sh"
+      - "buildscripts/check-release-state.sh"
+      - "buildscripts/check-release-state_test.sh"
       - "buildscripts/verify-rebrand.sh"
       - "buildscripts/verify-helm-migration.sh"
       - "buildscripts/helm-migration-guard/**"
@@ -479,6 +481,8 @@ jobs:
           bash -n buildscripts/minio-upgrade.sh
           bash -n buildscripts/sign-release-rpms.sh
           bash -n buildscripts/verify-build-provenance.sh
+          bash -n buildscripts/check-release-state.sh
+          bash -n buildscripts/check-release-state_test.sh
           bash -n buildscripts/verify-rebrand.sh
           bash -n buildscripts/verify-helm-migration.sh
           sh -n buildscripts/package/postinstall.sh
@@ -493,9 +497,12 @@ jobs:
           test -x buildscripts/package-release.sh
           test -x buildscripts/sign-release-rpms.sh
           test -x buildscripts/verify-build-provenance.sh
+          test -x buildscripts/check-release-state.sh
+          test -x buildscripts/check-release-state_test.sh
           test -x buildscripts/verify-rebrand.sh
           test -x buildscripts/verify-helm-migration.sh
           test -x buildscripts/package/postinstall.sh
           test -x buildscripts/package/preremove.sh
           test -x buildscripts/package/lifecycle_test.sh
           test -x dockerscripts/docker-entrypoint_test.sh
+          buildscripts/check-release-state_test.sh
diff --git a/buildscripts/check-release-state.sh b/buildscripts/check-release-state.sh
new file mode 100755
index 000000000..85dfb8ced
--- /dev/null
+++ b/buildscripts/check-release-state.sh
@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+
+# Fail closed before a release job can replace published or finalized assets.
+# An ordinary Draft is retry state; a finalized Draft contains GPG-derived
+# materials and must never be replaced by the build lane.
+
+set -euo pipefail
+
+release_tag="${1:-}"
+fixture="${2:-}"
+repository="${GITHUB_REPOSITORY:-pgsty/silo}"
+require_draft="${REQUIRE_DRAFT:-false}"
+
+if ! command -v jq >/dev/null 2>&1; then
+	echo "jq is required to inspect GitHub release state" >&2
+	exit 1
+fi
+
+if [[ ! "${release_tag}" =~ ^RELEASE\.[0-9]{4}-[0-9]{2}-[0-9]{2}T[0-9]{2}-[0-9]{2}-[0-9]{2}Z$ ]]; then
+	echo "Invalid release tag format: ${release_tag:-<empty>}" >&2
+	exit 1
+fi
+
+if [ -n "${fixture}" ]; then
+	release_json="$(<"${fixture}")"
+else
+	error_file="$(mktemp)"
+	trap 'rm -f "${error_file}"' EXIT
+	if ! release_json="$(
+		gh api --paginate "repos/${repository}/releases?per_page=100" --jq '.[]' 2>"${error_file}" |
+			jq --arg tag "${release_tag}" -s '[.[] | select(.tag_name == $tag)]'
+	)"; then
+		cat "${error_file}" >&2
+		exit 1
+	fi
+fi
+
+if ! jq -e 'type == "array" and all(.[]; type == "object" and (.tag_name | type == "string") and (.draft | type == "boolean"))' \
+	<<<"${release_json}" >/dev/null 2>&1; then
+	echo "Invalid release state response for ${release_tag}" >&2
+	exit 1
+fi
+
+if ! jq -e --arg tag "${release_tag}" 'all(.[]; .tag_name == $tag)' \
+	<<<"${release_json}" >/dev/null 2>&1; then
+	echo "Release state returned a tag other than ${release_tag}" >&2
+	exit 1
+fi
+
+release_count="$(jq 'length' <<<"${release_json}")"
+if [ "${release_count}" -eq 0 ]; then
+	if [ "${require_draft}" = "true" ]; then
+		echo "Expected one Draft release for ${release_tag}, found none" >&2
+		exit 1
+	fi
+	echo "No existing release for ${release_tag}."
+	exit 0
+fi
+
+if [ "${release_count}" -ne 1 ]; then
+	echo "Refusing to choose among ${release_count} releases for ${release_tag}; clean duplicate Drafts first" >&2
+	exit 1
+fi
+
+if [ "$(jq -r '.[0].draft' <<<"${release_json}")" != "true" ]; then
+	echo "Refusing to overwrite published release ${release_tag}" >&2
+	exit 1
+fi
+
+finalize_markers="$(jq '[.[0].assets[]? | select(.name | endswith("_packages_provenance.sigstore.json"))] | length' <<<"${release_json}")"
+if [ "${finalize_markers}" -ne 0 ]; then
+	echo "Refusing to replace finalized Draft ${release_tag}" >&2
+	exit 1
+fi
+
+echo "Existing unfinalized Draft ${release_tag} will be replaced from scratch."
diff --git a/buildscripts/check-release-state_test.sh b/buildscripts/check-release-state_test.sh
new file mode 100755
index 000000000..6e2b63779
--- /dev/null
+++ b/buildscripts/check-release-state_test.sh
@@ -0,0 +1,68 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+script_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+checker="${script_dir}/check-release-state.sh"
+tag="RELEASE.2026-08-29T00-00-00Z"
+fixture="$(mktemp)"
+stdout_file="$(mktemp)"
+stderr_file="$(mktemp)"
+trap 'rm -f "${fixture}" "${stdout_file}" "${stderr_file}"' EXIT
+
+expect_success() {
+	if ! "${checker}" "$@" >"${stdout_file}" 2>"${stderr_file}"; then
+		cat "${stderr_file}" >&2
+		return 1
+	fi
+}
+
+expect_failure() {
+	if "${checker}" "$@" >"${stdout_file}" 2>"${stderr_file}"; then
+		echo "Expected release-state check to fail: $*" >&2
+		return 1
+	fi
+}
+
+printf '[]\n' >"${fixture}"
+expect_success "${tag}" "${fixture}"
+grep -qF "No existing release for ${tag}." "${stdout_file}"
+
+if REQUIRE_DRAFT=true "${checker}" "${tag}" "${fixture}" >"${stdout_file}" 2>"${stderr_file}"; then
+	echo "Expected required-Draft check to fail when no release exists" >&2
+	exit 1
+fi
+grep -qF "Expected one Draft release for ${tag}, found none" "${stderr_file}"
+
+printf '[{"tag_name":"%s","draft":true,"assets":[]}]\n' "${tag}" >"${fixture}"
+expect_success "${tag}" "${fixture}"
+grep -qF "Existing unfinalized Draft ${tag} will be replaced from scratch." "${stdout_file}"
+if ! REQUIRE_DRAFT=true "${checker}" "${tag}" "${fixture}" >"${stdout_file}" 2>"${stderr_file}"; then
+	cat "${stderr_file}" >&2
+	exit 1
+fi
+
+printf '[{"tag_name":"%s","draft":true,"assets":[{"name":"silo_20260829000000.0.0_packages_provenance.sigstore.json"}]}]\n' "${tag}" >"${fixture}"
+expect_failure "${tag}" "${fixture}"
+grep -qF "Refusing to replace finalized Draft ${tag}" "${stderr_file}"
+
+printf '[{"tag_name":"%s","draft":false}]\n' "${tag}" >"${fixture}"
+expect_failure "${tag}" "${fixture}"
+grep -qF "Refusing to overwrite published release ${tag}" "${stderr_file}"
+
+printf '[{"tag_name":"%s","draft":true},{"tag_name":"%s","draft":true}]\n' "${tag}" "${tag}" >"${fixture}"
+expect_failure "${tag}" "${fixture}"
+grep -qF "Refusing to choose among 2 releases" "${stderr_file}"
+
+printf '[{"tag_name":"RELEASE.2026-08-28T00-00-00Z","draft":true}]\n' >"${fixture}"
+expect_failure "${tag}" "${fixture}"
+grep -qF "other than ${tag}" "${stderr_file}"
+
+printf '{not-json}\n' >"${fixture}"
+expect_failure "${tag}" "${fixture}"
+grep -qF "Invalid release state response for ${tag}" "${stderr_file}"
+
+expect_failure "not-a-release-tag" "${fixture}"
+grep -qF "Invalid release tag format" "${stderr_file}"
+
+echo "release-state decision tests passed"
diff --git a/cmd/admin-handlers-site-replication.go b/cmd/admin-handlers-site-replication.go
index ef74c9676..14dca5542 100644
--- a/cmd/admin-handlers-site-replication.go
+++ b/cmd/admin-handlers-site-replication.go
@@ -255,7 +255,7 @@ func (a adminAPIHandlers) SRPeerReplicateBucketItem(w http.ResponseWriter, r *ht
 	case madmin.SRBucketMetaTypeTags:
 		err = globalSiteReplicationSys.PeerBucketTaggingHandler(ctx, item.Bucket, item.Tags, item.UpdatedAt)
 	case madmin.SRBucketMetaTypeObjectLockConfig:
-		err = globalSiteReplicationSys.PeerBucketObjectLockConfigHandler(ctx, item.Bucket, item.ObjectLockConfig, item.UpdatedAt)
+		err = globalSiteReplicationSys.peerBucketObjectLockConfigItem(ctx, item)
 	case madmin.SRBucketMetaTypeSSEConfig:
 		err = globalSiteReplicationSys.PeerBucketSSEConfigHandler(ctx, item.Bucket, item.SSEConfig, item.UpdatedAt)
 	case madmin.SRBucketMetaTypeCorsConfig:
diff --git a/cmd/api-router.go b/cmd/api-router.go
index 8de86e9bb..63164a06c 100644
--- a/cmd/api-router.go
+++ b/cmd/api-router.go
@@ -785,19 +785,21 @@ func corsHandler(handler http.Handler) http.Handler {
 	}
 	globalCors := cors.New(opts).Handler(handler)
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if bucket, _ := request2BucketObjectName(r); bucket != "" && globalBucketMetadataSys != nil {
-			cfg, _, err := globalBucketMetadataSys.GetCorsConfig(bucket)
-			if err == nil && cfg != nil {
-				if applyBucketCors(w, r, cfg) {
+		if r.Header.Get("Origin") != "" {
+			if bucket, _ := request2BucketObjectName(r); bucket != "" && globalBucketMetadataSys != nil {
+				cfg, _, err := globalBucketMetadataSys.GetCorsConfig(bucket)
+				if err == nil && cfg != nil {
+					if applyBucketCors(w, r, cfg) {
+						return
+					}
+					handler.ServeHTTP(w, r)
+					return
+				}
+				if err != nil && !errors.Is(err, errConfigNotFound) {
+					internalLogOnceIf(r.Context(), err, "bucket-cors-metadata")
+					handler.ServeHTTP(w, r)
 					return
 				}
-				handler.ServeHTTP(w, r)
-				return
-			}
-			if err != nil && !errors.Is(err, errConfigNotFound) && r.Header.Get("Origin") != "" {
-				internalLogOnceIf(r.Context(), err, "bucket-cors-metadata")
-				handler.ServeHTTP(w, r)
-				return
 			}
 		}
 		globalCors.ServeHTTP(w, r)
diff --git a/cmd/bucket-cors-middleware_test.go b/cmd/bucket-cors-middleware_test.go
index be6d1ddda..f168e0f31 100644
--- a/cmd/bucket-cors-middleware_test.go
+++ b/cmd/bucket-cors-middleware_test.go
@@ -18,15 +18,27 @@
 package cmd
 
 import (
+	"context"
 	"net/http"
 	"net/http/httptest"
 	"strings"
+	"sync/atomic"
 	"testing"
 
 	"github.com/minio/minio/internal/auth"
 	"github.com/minio/minio/internal/bucket/cors"
 )
 
+type corsLookupCountingObjectLayer struct {
+	ObjectLayer
+	getObjectNInfoCalls atomic.Int64
+}
+
+func (o *corsLookupCountingObjectLayer) GetObjectNInfo(ctx context.Context, bucket, object string, rs *HTTPRangeSpec, h http.Header, opts ObjectOptions) (*GetObjectReader, error) {
+	o.getObjectNInfoCalls.Add(1)
+	return o.ObjectLayer.GetObjectNInfo(ctx, bucket, object, rs, h, opts)
+}
+
 func TestPerBucketCorsPreflight(t *testing.T) {
 	cfg := &cors.Config{CORSRules: []cors.Rule{{
 		AllowedOrigins: []string{"http://example.com"},
@@ -245,8 +257,13 @@ func TestPerBucketCorsOriginPatternResponse(t *testing.T) {
 
 func TestBucketCorsMetadataErrorFailsClosed(t *testing.T) {
 	oldObjectAPI := newObjectLayerFn()
+	oldMetadataSys := globalBucketMetadataSys
 	setObjectLayer(nil)
-	defer setObjectLayer(oldObjectAPI)
+	globalBucketMetadataSys = NewBucketMetadataSys()
+	defer func() {
+		setObjectLayer(oldObjectAPI)
+		globalBucketMetadataSys = oldMetadataSys
+	}()
 
 	wrapped := corsHandler(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		w.WriteHeader(http.StatusNoContent)
@@ -273,6 +290,55 @@ func TestBucketCorsMetadataErrorFailsClosed(t *testing.T) {
 	}
 }
 
+func TestBucketCorsSkipsMetadataLookupWithoutOrigin(t *testing.T) {
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testBucketCorsSkipsMetadataLookupWithoutOrigin,
+		endpoints:  []string{"GetObject"},
+	})
+}
+
+func testBucketCorsSkipsMetadataLookupWithoutOrigin(obj ObjectLayer, _ string, _ string, _ http.Handler, _ auth.Credentials, t *testing.T) {
+	oldObjectAPI := newObjectLayerFn()
+	counting := &corsLookupCountingObjectLayer{ObjectLayer: obj}
+	setObjectLayer(counting)
+	defer setObjectLayer(oldObjectAPI)
+
+	wrapped := corsHandler(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusNoContent)
+	}))
+	rec := httptest.NewRecorder()
+	wrapped.ServeHTTP(rec, httptest.NewRequest(http.MethodGet, getGetObjectURL("", "api", "v1/login"), nil))
+
+	if rec.Code != http.StatusNoContent {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusNoContent)
+	}
+	requireCorsOriginVary(t, rec.Header())
+	if got := counting.getObjectNInfoCalls.Load(); got != 0 {
+		t.Fatalf("request without Origin performed %d bucket metadata reads", got)
+	}
+}
+
+func TestBucketCorsOriginlessPreflightShapeUsesGlobalHandler(t *testing.T) {
+	nextCalled := false
+	wrapped := corsHandler(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		nextCalled = true
+		w.WriteHeader(http.StatusTeapot)
+	}))
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodOptions, getGetObjectURL("", "api", "v1/login"), nil)
+	req.Header.Set("Access-Control-Request-Method", http.MethodGet)
+	wrapped.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusNoContent {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusNoContent)
+	}
+	if nextCalled {
+		t.Fatal("originless preflight-shaped OPTIONS reached the application handler")
+	}
+	requireCorsOriginVary(t, rec.Header())
+}
+
 func TestBucketCorsNoConfigUsesGlobalFallback(t *testing.T) {
 	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
 		t:          t,
@@ -281,6 +347,34 @@ func TestBucketCorsNoConfigUsesGlobalFallback(t *testing.T) {
 	})
 }
 
+func TestBucketCorsMissingBucketUsesGlobalFallback(t *testing.T) {
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testBucketCorsMissingBucketUsesGlobalFallback,
+		endpoints:  []string{"GetBucketCors"},
+	})
+}
+
+func testBucketCorsMissingBucketUsesGlobalFallback(_ ObjectLayer, _ string, bucket string, _ http.Handler, _ auth.Credentials, t *testing.T) {
+	wrapped := corsHandler(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+	}))
+	rec := httptest.NewRecorder()
+	req := httptest.NewRequest(http.MethodGet, getGetObjectURL("", bucket+"-missing", "object"), nil)
+	req.Header.Set("Origin", "https://app.example.com")
+	wrapped.ServeHTTP(rec, req)
+
+	if rec.Code != http.StatusNotFound {
+		t.Fatalf("status = %d, want %d", rec.Code, http.StatusNotFound)
+	}
+	if got := rec.Header().Get("Access-Control-Allow-Origin"); got != "https://app.example.com" {
+		t.Fatalf("allow-origin = %q", got)
+	}
+	if got := rec.Header().Get("Access-Control-Allow-Credentials"); got != "true" {
+		t.Fatalf("allow-credentials = %q", got)
+	}
+}
+
 func testBucketCorsNoConfigUsesGlobalFallback(_ ObjectLayer, _ string, bucket string, _ http.Handler, _ auth.Credentials, t *testing.T) {
 	wrapped := corsHandler(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		w.WriteHeader(http.StatusNoContent)
diff --git a/cmd/bucket-handlers.go b/cmd/bucket-handlers.go
index 9be23c21d..47096cbf0 100644
--- a/cmd/bucket-handlers.go
+++ b/cmd/bucket-handlers.go
@@ -1844,12 +1844,7 @@ func (api objectAPIHandlers) PutBucketObjectLockConfigHandler(w http.ResponseWri
 	// We encode the xml bytes as base64 to ensure there are no encoding
 	// errors.
 	cfgStr := base64.StdEncoding.EncodeToString(configData)
-	replLogIf(ctx, globalSiteReplicationSys.BucketMetaHook(ctx, madmin.SRBucketMeta{
-		Type:             madmin.SRBucketMetaTypeObjectLockConfig,
-		Bucket:           bucket,
-		ObjectLockConfig: &cfgStr,
-		UpdatedAt:        updatedAt,
-	}))
+	replLogIf(ctx, globalSiteReplicationSys.BucketMetaHook(ctx, newSRBucketObjectLockMeta(bucket, &cfgStr, updatedAt)))
 
 	// Write success response.
 	writeSuccessResponseHeadersOnly(w)
diff --git a/cmd/bucket-metadata.go b/cmd/bucket-metadata.go
index ba4c0eb5b..9c066ba32 100644
--- a/cmd/bucket-metadata.go
+++ b/cmd/bucket-metadata.go
@@ -344,7 +344,10 @@ func (b *BucketMetadata) parseAllConfigs(ctx context.Context, objectAPI ObjectLa
 	}
 
 	if bytes.Equal(b.ObjectLockConfigXML, enabledBucketObjectLockConfig) {
-		b.VersioningConfigXML = enabledBucketVersioningConfig
+		config, versioningErr := versioning.ParseConfig(bytes.NewReader(b.VersioningConfigXML))
+		if versioningErr != nil || !config.Enabled() {
+			b.VersioningConfigXML = enabledBucketVersioningConfig
+		}
 	}
 
 	if len(b.ObjectLockConfigXML) != 0 {
diff --git a/cmd/erasure-multipart-fullobject_test.go b/cmd/erasure-multipart-fullobject_test.go
index c8f3dde11..bb196acda 100644
--- a/cmd/erasure-multipart-fullobject_test.go
+++ b/cmd/erasure-multipart-fullobject_test.go
@@ -516,17 +516,33 @@ func testAPICompleteMultipartChecksumTypeMismatch(obj ObjectLayer, instanceType,
 		}
 	})
 
-	t.Run("crc64nvme-composite-completion-is-rejected", func(t *testing.T) {
+	t.Run("crc64nvme-composite-is-rejected", func(t *testing.T) {
 		crc64Type := hash.ChecksumCRC64NVME
 		objectName := "type-mismatch/crc64nvme-composite"
-		uploadID := newMultipartUploadHTTP(t, apiRouter, credentials, bucketName, objectName,
-			crc64Type.String(), xhttp.AmzChecksumTypeComposite)
-		etags := uploadPartsHTTP(t, apiRouter, credentials, bucketName, objectName, uploadID, crc64Type, partData)
-		rec := completeMultipartUploadHTTP(t, apiRouter, credentials, bucketName, objectName, uploadID, etags, nil,
-			map[string]string{
-				crc64Type.Key():       mustChecksum(t, crc64Type, full),
+		req, err := newTestSignedRequestV4(http.MethodPost, getNewMultipartURL("", bucketName, objectName),
+			0, nil, credentials.AccessKey, credentials.SecretKey, map[string]string{
+				xhttp.AmzChecksumAlgo: crc64Type.String(),
 				xhttp.AmzChecksumType: xhttp.AmzChecksumTypeComposite,
 			})
+		if err != nil {
+			t.Fatal(err)
+		}
+		rec := httptest.NewRecorder()
+		apiRouter.ServeHTTP(rec, req)
+		if rec.Code != http.StatusBadRequest || apiErrorCode(t, rec) != "InvalidArgument" {
+			t.Fatalf("%s: CRC64NVME/COMPOSITE returned %d %s", instanceType, rec.Code, rec.Body.String())
+		}
+	})
+
+	t.Run("crc64nvme-composite-completion-is-rejected", func(t *testing.T) {
+		crc64Type := hash.ChecksumCRC64NVME
+		objectName := "type-mismatch/crc64nvme-composite-completion"
+		uploadID := newMultipartUploadHTTP(t, apiRouter, credentials, bucketName, objectName,
+			crc64Type.String(), xhttp.AmzChecksumTypeFullObject)
+		etags := uploadPartsHTTP(t, apiRouter, credentials, bucketName, objectName, uploadID, crc64Type, partData)
+		partCS := []string{mustChecksum(t, crc64Type, partData[0]), mustChecksum(t, crc64Type, partData[1])}
+		rec := completeMultipartUploadHTTP(t, apiRouter, credentials, bucketName, objectName, uploadID, etags, partCS,
+			map[string]string{xhttp.AmzChecksumType: xhttp.AmzChecksumTypeComposite})
 		if rec.Code != http.StatusBadRequest || apiErrorCode(t, rec) != "BadDigest" {
 			t.Fatalf("%s: CRC64NVME composite completion returned %d %s", instanceType, rec.Code, rec.Body.String())
 		}
diff --git a/cmd/object-api-options.go b/cmd/object-api-options.go
index 0d496e811..c20a40b8e 100644
--- a/cmd/object-api-options.go
+++ b/cmd/object-api-options.go
@@ -439,6 +439,9 @@ func putOptsFromHeaders(ctx context.Context, hdr http.Header, metadata map[strin
 
 // get ObjectOptions for Copy calls with encryption headers provided on the target side and source side metadata
 func copyDstOpts(ctx context.Context, r *http.Request, bucket, object string, metadata map[string]string) (opts ObjectOptions, err error) {
+	if _, err := hash.GetContentChecksum(r.Header); err != nil {
+		return opts, err
+	}
 	return putOptsFromReq(ctx, r, bucket, object, metadata)
 }
 
diff --git a/cmd/object-checksum-unsupported_test.go b/cmd/object-checksum-unsupported_test.go
new file mode 100644
index 000000000..be11f8e9c
--- /dev/null
+++ b/cmd/object-checksum-unsupported_test.go
@@ -0,0 +1,137 @@
+// Copyright (c) 2015-2026 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cmd
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/xml"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+
+	"github.com/minio/minio/internal/auth"
+	xhttp "github.com/minio/minio/internal/http"
+)
+
+func TestAPIRejectsUnsupportedChecksumHeaders(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testAPIRejectsUnsupportedChecksumHeaders,
+		endpoints:  []string{"CopyObject", "NewMultipart", "PutObject", "PutObjectPart"},
+	})
+}
+
+func testAPIRejectsUnsupportedChecksumHeaders(obj ObjectLayer, instanceType, bucketName string,
+	apiRouter http.Handler, credentials auth.Credentials, t *testing.T,
+) {
+	data := []byte("unsupported-checksum")
+	unsupportedValue := base64.StdEncoding.EncodeToString(make([]byte, 64))
+
+	put := func(object string, headers map[string]string) *httptest.ResponseRecorder {
+		t.Helper()
+		req, err := newTestSignedRequestV4(http.MethodPut, getPutObjectURL("", bucketName, object),
+			int64(len(data)), bytes.NewReader(data), credentials.AccessKey, credentials.SecretKey, headers)
+		if err != nil {
+			t.Fatal(err)
+		}
+		rec := httptest.NewRecorder()
+		apiRouter.ServeHTTP(rec, req)
+		return rec
+	}
+	assertRejected := func(name string, rec *httptest.ResponseRecorder) {
+		t.Helper()
+		if rec.Code != http.StatusBadRequest || !strings.Contains(rec.Body.String(), "<Code>InvalidArgument</Code>") {
+			t.Fatalf("%s: %s returned %d, want InvalidArgument: %s", instanceType, name, rec.Code, rec.Body.String())
+		}
+	}
+
+	for _, algorithm := range []string{"md5", "sha512", "xxhash64", "xxhash3", "xxhash128", "future"} {
+		object := "checksums/unsupported-" + algorithm
+		assertRejected(algorithm, put(object, map[string]string{
+			"x-amz-sdk-checksum-algorithm": "SHA512",
+			"x-amz-checksum-" + algorithm:  unsupportedValue,
+		}))
+		if _, err := obj.GetObjectInfo(t.Context(), bucketName, object, ObjectOptions{}); !isErrObjectNotFound(err) {
+			t.Fatalf("%s: rejected %s checksum stored an object: %v", instanceType, algorithm, err)
+		}
+	}
+
+	assertRejected("unsupported trailer", put("checksums/unsupported-trailer", map[string]string{
+		xhttp.AmzTrailer: "x-amz-checksum-sha512",
+	}))
+
+	newMultipart := func(name string, headers map[string]string) *httptest.ResponseRecorder {
+		t.Helper()
+		req, err := newTestSignedRequestV4(http.MethodPost, getNewMultipartURL("", bucketName, name),
+			0, nil, credentials.AccessKey, credentials.SecretKey, headers)
+		if err != nil {
+			t.Fatal(err)
+		}
+		rec := httptest.NewRecorder()
+		apiRouter.ServeHTTP(rec, req)
+		return rec
+	}
+	assertRejected("NewMultipartUpload value header", newMultipart("checksums/mp-value", map[string]string{
+		"x-amz-checksum-sha512": unsupportedValue,
+	}))
+	assertRejected("NewMultipartUpload trailer", newMultipart("checksums/mp-trailer", map[string]string{
+		xhttp.AmzTrailer: "x-amz-checksum-sha512",
+	}))
+
+	rec := newMultipart("checksums/mp-part", nil)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("%s: NewMultipartUpload setup returned %d: %s", instanceType, rec.Code, rec.Body.String())
+	}
+	var initiated InitiateMultipartUploadResponse
+	if err := xml.Unmarshal(rec.Body.Bytes(), &initiated); err != nil {
+		t.Fatal(err)
+	}
+	req, err := newTestSignedRequestV4(http.MethodPut,
+		getPutObjectPartURL("", bucketName, "checksums/mp-part", initiated.UploadID, "1"),
+		int64(len(data)), bytes.NewReader(data), credentials.AccessKey, credentials.SecretKey,
+		map[string]string{"x-amz-checksum-sha512": unsupportedValue})
+	if err != nil {
+		t.Fatal(err)
+	}
+	rec = httptest.NewRecorder()
+	apiRouter.ServeHTTP(rec, req)
+	assertRejected("UploadPart", rec)
+	parts, err := obj.ListObjectParts(t.Context(), bucketName, "checksums/mp-part", initiated.UploadID, 0, 1000, ObjectOptions{})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(parts.Parts) != 0 {
+		t.Fatalf("%s: rejected UploadPart stored %d parts", instanceType, len(parts.Parts))
+	}
+	if err := obj.AbortMultipartUpload(t.Context(), bucketName, "checksums/mp-part", initiated.UploadID, ObjectOptions{}); err != nil {
+		t.Fatal(err)
+	}
+
+	source := "checksums/source"
+	putCopyChecksumSource(t, apiRouter, credentials, bucketName, source, data, nil)
+	rec = copyChecksumRequest(t, apiRouter, credentials, bucketName, source, "checksums/copy", map[string]string{
+		"x-amz-checksum-sha512": unsupportedValue,
+	})
+	assertRejected("CopyObject", rec)
+	if _, err := obj.GetObjectInfo(t.Context(), bucketName, "checksums/copy", ObjectOptions{}); !isErrObjectNotFound(err) {
+		t.Fatalf("%s: rejected CopyObject stored a destination: %v", instanceType, err)
+	}
+}
diff --git a/cmd/object-crc64-composite_test.go b/cmd/object-crc64-composite_test.go
new file mode 100644
index 000000000..70a80370d
--- /dev/null
+++ b/cmd/object-crc64-composite_test.go
@@ -0,0 +1,79 @@
+// Copyright (c) 2015-2026 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cmd
+
+import (
+	"bytes"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/minio/minio/internal/auth"
+	"github.com/minio/minio/internal/hash"
+	xhttp "github.com/minio/minio/internal/http"
+)
+
+func TestAPIPutObjectRejectsCRC64Composite(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testAPIPutObjectRejectsCRC64Composite,
+		endpoints:  []string{"PutObject"},
+	})
+}
+
+func testAPIPutObjectRejectsCRC64Composite(obj ObjectLayer, instanceType, bucketName string,
+	apiRouter http.Handler, credentials auth.Credentials, t *testing.T,
+) {
+	data := []byte("crc64-composite")
+	object := "checksums/crc64-composite"
+	req, err := newTestSignedRequestV4(http.MethodPut, getPutObjectURL("", bucketName, object),
+		int64(len(data)), bytes.NewReader(data), credentials.AccessKey, credentials.SecretKey, map[string]string{
+			xhttp.AmzChecksumCRC64NVME: mustChecksum(t, hash.ChecksumCRC64NVME, data),
+			xhttp.AmzChecksumType:      xhttp.AmzChecksumTypeComposite,
+		})
+	if err != nil {
+		t.Fatal(err)
+	}
+	rec := httptest.NewRecorder()
+	apiRouter.ServeHTTP(rec, req)
+	if rec.Code != http.StatusBadRequest || apiErrorCode(t, rec) != "InvalidArgument" {
+		t.Fatalf("%s: CRC64NVME/COMPOSITE PutObject returned %d %s", instanceType, rec.Code, rec.Body.String())
+	}
+	if _, err := obj.GetObjectInfo(t.Context(), bucketName, object, ObjectOptions{}); !isErrObjectNotFound(err) {
+		t.Fatalf("%s: rejected PutObject stored an object: %v", instanceType, err)
+	}
+
+	trailerObject := "checksums/crc64-composite-trailer"
+	req, err = newTestSignedRequestV4(http.MethodPut, getPutObjectURL("", bucketName, trailerObject),
+		int64(len(data)), bytes.NewReader(data), credentials.AccessKey, credentials.SecretKey, map[string]string{
+			xhttp.AmzTrailer:      xhttp.AmzChecksumCRC64NVME,
+			xhttp.AmzChecksumType: xhttp.AmzChecksumTypeComposite,
+		})
+	if err != nil {
+		t.Fatal(err)
+	}
+	rec = httptest.NewRecorder()
+	apiRouter.ServeHTTP(rec, req)
+	if rec.Code != http.StatusBadRequest || apiErrorCode(t, rec) != "InvalidArgument" {
+		t.Fatalf("%s: trailing CRC64NVME/COMPOSITE PutObject returned %d %s", instanceType, rec.Code, rec.Body.String())
+	}
+	if _, err := obj.GetObjectInfo(t.Context(), bucketName, trailerObject, ObjectOptions{}); !isErrObjectNotFound(err) {
+		t.Fatalf("%s: rejected trailing PutObject stored an object: %v", instanceType, err)
+	}
+}
diff --git a/cmd/object-multipart-handlers.go b/cmd/object-multipart-handlers.go
index 2f6a68a94..37ff9f880 100644
--- a/cmd/object-multipart-handlers.go
+++ b/cmd/object-multipart-handlers.go
@@ -309,6 +309,10 @@ func (api objectAPIHandlers) NewMultipartUploadHandler(w http.ResponseWriter, r
 		}
 	}
 
+	if _, err := hash.GetContentChecksum(r.Header); err != nil {
+		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidChecksum), r.URL)
+		return
+	}
 	checksumType := hash.NewChecksumHeader(r.Header)
 	if checksumType.Is(hash.ChecksumInvalid) {
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrInvalidChecksum), r.URL)
diff --git a/cmd/site-replication-bucket-adoption_test.go b/cmd/site-replication-bucket-adoption_test.go
new file mode 100644
index 000000000..2a5d98b3d
--- /dev/null
+++ b/cmd/site-replication-bucket-adoption_test.go
@@ -0,0 +1,190 @@
+// Copyright (c) 2015-2026 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cmd
+
+import (
+	"bytes"
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/minio/minio/internal/auth"
+)
+
+func TestPeerBucketAdoptionPreservesLockAndVersioningConfigs(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:                 t,
+		objAPITest:        testPeerBucketAdoptionPreservesLockAndVersioningConfigs,
+		makeBucketOptions: MakeBucketOptions{LockEnabled: true},
+	})
+}
+
+func testPeerBucketAdoptionPreservesLockAndVersioningConfigs(_ ObjectLayer, instanceType, bucketName string,
+	_ http.Handler, _ auth.Credentials, t *testing.T,
+) {
+	objectLockXML := []byte(`<ObjectLockConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><ObjectLockEnabled>Enabled</ObjectLockEnabled><Rule><DefaultRetention><Mode>GOVERNANCE</Mode><Days>30</Days></DefaultRetention></Rule></ObjectLockConfiguration>`)
+	versioningXML := []byte(`<VersioningConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><Status>Enabled</Status><ExcludeFolders>true</ExcludeFolders><ExcludedPrefixes><Prefix>temporary/</Prefix></ExcludedPrefixes></VersioningConfiguration>`)
+	if _, err := globalBucketMetadataSys.Update(t.Context(), bucketName, objectLockConfig, objectLockXML); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := globalBucketMetadataSys.Update(t.Context(), bucketName, bucketVersioningConfig, versioningXML); err != nil {
+		t.Fatal(err)
+	}
+	before, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := globalSiteReplicationSys.PeerBucketMakeWithVersioningHandler(t.Context(), bucketName, MakeBucketOptions{
+		CreatedAt:   before.Created.Add(-time.Hour),
+		LockEnabled: true,
+	}); err != nil {
+		t.Fatalf("%s: adopting existing bucket failed: %v", instanceType, err)
+	}
+	after, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(after.ObjectLockConfigXML, before.ObjectLockConfigXML) || !after.ObjectLockConfigUpdatedAt.Equal(before.ObjectLockConfigUpdatedAt) {
+		t.Fatalf("%s: Object Lock config changed during adoption", instanceType)
+	}
+	if !bytes.Equal(after.VersioningConfigXML, before.VersioningConfigXML) || !after.VersioningConfigUpdatedAt.Equal(before.VersioningConfigUpdatedAt) {
+		t.Fatalf("%s: versioning config changed during adoption", instanceType)
+	}
+}
+
+func TestPeerBucketAdoptionBootstrapsMissingConfigs(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testPeerBucketAdoptionBootstrapsMissingConfigs,
+	})
+}
+
+func TestPeerBucketAdoptionPreservesCustomVersioningWhenEnablingLock(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testPeerBucketAdoptionPreservesCustomVersioningWhenEnablingLock,
+	})
+}
+
+func testPeerBucketAdoptionPreservesCustomVersioningWhenEnablingLock(_ ObjectLayer, instanceType, bucketName string,
+	_ http.Handler, _ auth.Credentials, t *testing.T,
+) {
+	versioningXML := []byte(`<VersioningConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><Status>Enabled</Status><ExcludeFolders>true</ExcludeFolders><ExcludedPrefixes><Prefix>temporary/</Prefix></ExcludedPrefixes></VersioningConfiguration>`)
+	if _, err := globalBucketMetadataSys.Update(t.Context(), bucketName, bucketVersioningConfig, versioningXML); err != nil {
+		t.Fatal(err)
+	}
+	before, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := globalSiteReplicationSys.PeerBucketMakeWithVersioningHandler(t.Context(), bucketName, MakeBucketOptions{
+		CreatedAt:   before.Created,
+		LockEnabled: true,
+	}); err != nil {
+		t.Fatal(err)
+	}
+	after, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(after.VersioningConfigXML, before.VersioningConfigXML) || !after.VersioningConfigUpdatedAt.Equal(before.VersioningConfigUpdatedAt) {
+		t.Fatalf("%s: custom versioning changed while enabling Object Lock", instanceType)
+	}
+	if !bytes.Equal(after.ObjectLockConfigXML, enabledBucketObjectLockConfig) {
+		t.Fatalf("%s: Object Lock was not bootstrapped", instanceType)
+	}
+}
+
+func TestPeerBucketAdoptionEnablesSuspendedVersioning(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testPeerBucketAdoptionEnablesSuspendedVersioning,
+	})
+}
+
+func testPeerBucketAdoptionEnablesSuspendedVersioning(_ ObjectLayer, instanceType, bucketName string,
+	_ http.Handler, _ auth.Credentials, t *testing.T,
+) {
+	suspended := []byte(`<VersioningConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><Status>Suspended</Status></VersioningConfiguration>`)
+	if _, err := globalBucketMetadataSys.Update(t.Context(), bucketName, bucketVersioningConfig, suspended); err != nil {
+		t.Fatal(err)
+	}
+	before, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := globalSiteReplicationSys.PeerBucketMakeWithVersioningHandler(t.Context(), bucketName, MakeBucketOptions{CreatedAt: before.Created}); err != nil {
+		t.Fatal(err)
+	}
+	after, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if after.versioningConfig == nil || !after.versioningConfig.Enabled() {
+		t.Fatalf("%s: versioning remained disabled: %q", instanceType, after.VersioningConfigXML)
+	}
+	if !after.VersioningConfigUpdatedAt.After(before.VersioningConfigUpdatedAt) {
+		t.Fatalf("%s: versioning update time = %v, want after %v", instanceType, after.VersioningConfigUpdatedAt, before.VersioningConfigUpdatedAt)
+	}
+}
+
+func TestEnablePeerBucketVersioningRepairsInvalidConfig(t *testing.T) {
+	meta := newBucketMetadata("bucket")
+	meta.Created = time.Date(2026, time.August, 29, 8, 0, 0, 0, time.UTC)
+	meta.VersioningConfigXML = []byte(`<VersioningConfiguration>`)
+	if err := enablePeerBucketVersioning(&meta); err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(meta.VersioningConfigXML, enabledBucketVersioningConfig) || meta.VersioningConfigUpdatedAt.IsZero() {
+		t.Fatalf("invalid versioning was not repaired: xml=%q updatedAt=%v", meta.VersioningConfigXML, meta.VersioningConfigUpdatedAt)
+	}
+}
+
+func testPeerBucketAdoptionBootstrapsMissingConfigs(_ ObjectLayer, instanceType, bucketName string,
+	_ http.Handler, _ auth.Credentials, t *testing.T,
+) {
+	before, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if len(before.ObjectLockConfigXML) != 0 || len(before.VersioningConfigXML) != 0 {
+		t.Fatalf("%s: invalid bootstrap precondition", instanceType)
+	}
+	if err := globalSiteReplicationSys.PeerBucketMakeWithVersioningHandler(t.Context(), bucketName, MakeBucketOptions{
+		CreatedAt:   before.Created,
+		LockEnabled: true,
+	}); err != nil {
+		t.Fatalf("%s: adopting existing bucket failed: %v", instanceType, err)
+	}
+	after, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !bytes.Equal(after.ObjectLockConfigXML, enabledBucketObjectLockConfig) || !bytes.Equal(after.VersioningConfigXML, enabledBucketVersioningConfig) {
+		t.Fatalf("%s: missing bootstrap configs: objectLock=%q versioning=%q", instanceType, after.ObjectLockConfigXML, after.VersioningConfigXML)
+	}
+	if !after.ObjectLockConfigUpdatedAt.Equal(before.Created) || !after.VersioningConfigUpdatedAt.Equal(before.Created) {
+		t.Fatalf("%s: bootstrap timestamps = (%v, %v), want %v", instanceType,
+			after.ObjectLockConfigUpdatedAt, after.VersioningConfigUpdatedAt, before.Created)
+	}
+}
diff --git a/cmd/site-replication-object-lock_test.go b/cmd/site-replication-object-lock_test.go
new file mode 100644
index 000000000..48d1d35f5
--- /dev/null
+++ b/cmd/site-replication-object-lock_test.go
@@ -0,0 +1,266 @@
+// Copyright (c) 2015-2026 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cmd
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/json"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/minio/madmin-go/v3"
+	"github.com/minio/minio/internal/auth"
+	"github.com/minio/mux"
+)
+
+func TestSRBucketObjectLockMetadata(t *testing.T) {
+	updatedAt := time.Date(2026, time.August, 29, 8, 0, 0, 0, time.UTC)
+	current := "current"
+	legacy := "legacy"
+
+	event := newSRBucketObjectLockMeta("bucket", &current, updatedAt)
+	if event.Type != madmin.SRBucketMetaTypeObjectLockConfig || event.Bucket != "bucket" ||
+		event.ObjectLockConfig == nil || *event.ObjectLockConfig != current || event.Tags != nil || !event.UpdatedAt.Equal(updatedAt) {
+		t.Fatalf("unexpected Object Lock event: %#v", event)
+	}
+
+	encoded, err := json.Marshal(event)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var roundTrip madmin.SRBucketMeta
+	if err := json.Unmarshal(encoded, &roundTrip); err != nil {
+		t.Fatal(err)
+	}
+	if roundTrip.ObjectLockConfig == nil || *roundTrip.ObjectLockConfig != current || roundTrip.Tags != nil {
+		t.Fatalf("unexpected JSON round trip: %#v", roundTrip)
+	}
+
+	for _, test := range []struct {
+		name string
+		item madmin.SRBucketMeta
+		want *string
+	}{
+		{name: "current", item: madmin.SRBucketMeta{ObjectLockConfig: &current}, want: &current},
+		{name: "legacy", item: madmin.SRBucketMeta{Tags: &legacy}, want: &legacy},
+		{name: "current wins", item: madmin.SRBucketMeta{ObjectLockConfig: &current, Tags: &legacy}, want: &current},
+		{name: "missing", item: madmin.SRBucketMeta{}},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			got := srObjectLockPayload(test.item)
+			if test.want == nil {
+				if got != nil {
+					t.Fatalf("payload = %q, want nil", *got)
+				}
+				return
+			}
+			if got == nil || *got != *test.want {
+				t.Fatalf("payload = %v, want %q", got, *test.want)
+			}
+		})
+	}
+}
+
+func TestPeerBucketObjectLockMetadataCurrentAndLegacyPayloads(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:                 t,
+		objAPITest:        testPeerBucketObjectLockMetadataCurrentAndLegacyPayloads,
+		makeBucketOptions: MakeBucketOptions{LockEnabled: true},
+	})
+}
+
+func applySRBucketMetaViaAdmin(t *testing.T, credentials auth.Credentials, item madmin.SRBucketMeta) *httptest.ResponseRecorder {
+	t.Helper()
+	body, err := json.Marshal(item)
+	if err != nil {
+		t.Fatal(err)
+	}
+	adminRouter := mux.NewRouter()
+	registerAdminRouter(adminRouter, true)
+	path := adminPathPrefix + adminAPIVersionPrefix + "/site-replication/peer/bucket-meta"
+	req, err := newTestSignedRequestV4(http.MethodPut, path, int64(len(body)), bytes.NewReader(body),
+		credentials.AccessKey, credentials.SecretKey, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	rec := httptest.NewRecorder()
+	adminRouter.ServeHTTP(rec, req)
+	return rec
+}
+
+func testPeerBucketObjectLockMetadataCurrentAndLegacyPayloads(_ ObjectLayer, instanceType, bucketName string,
+	_ http.Handler, credentials auth.Credentials, t *testing.T,
+) {
+	apply := func(item madmin.SRBucketMeta, wantDays uint64) {
+		t.Helper()
+		rec := applySRBucketMetaViaAdmin(t, credentials, item)
+		if rec.Code != http.StatusOK {
+			t.Fatalf("%s: admin Object Lock apply returned %d: %s", instanceType, rec.Code, rec.Body.String())
+		}
+		config, _, err := globalBucketMetadataSys.GetObjectLockConfig(bucketName)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if config.Rule == nil || config.Rule.DefaultRetention.Mode != "GOVERNANCE" ||
+			config.Rule.DefaultRetention.Days == nil || *config.Rule.DefaultRetention.Days != wantDays {
+			t.Fatalf("%s: persisted Object Lock config = %s, want GOVERNANCE/%d days", instanceType, config, wantDays)
+		}
+	}
+
+	config30 := base64.StdEncoding.EncodeToString([]byte(`<ObjectLockConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><ObjectLockEnabled>Enabled</ObjectLockEnabled><Rule><DefaultRetention><Mode>GOVERNANCE</Mode><Days>30</Days></DefaultRetention></Rule></ObjectLockConfiguration>`))
+	apply(newSRBucketObjectLockMeta(bucketName, &config30, UTCNow().Add(time.Hour)), 30)
+
+	config45 := base64.StdEncoding.EncodeToString([]byte(`<ObjectLockConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><ObjectLockEnabled>Enabled</ObjectLockEnabled><Rule><DefaultRetention><Mode>GOVERNANCE</Mode><Days>45</Days></DefaultRetention></Rule></ObjectLockConfiguration>`))
+	apply(madmin.SRBucketMeta{
+		Type:      madmin.SRBucketMetaTypeObjectLockConfig,
+		Bucket:    bucketName,
+		Tags:      &config45,
+		UpdatedAt: UTCNow().Add(2 * time.Hour),
+	}, 45)
+}
+
+func TestPeerBucketObjectLockMetadataWithoutLockEnabled(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testPeerBucketObjectLockMetadataWithoutLockEnabled,
+	})
+}
+
+func testPeerBucketObjectLockMetadataWithoutLockEnabled(_ ObjectLayer, instanceType, bucketName string,
+	_ http.Handler, credentials auth.Credentials, t *testing.T,
+) {
+	config := base64.StdEncoding.EncodeToString([]byte(`<ObjectLockConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><ObjectLockEnabled>Enabled</ObjectLockEnabled><Rule><DefaultRetention><Mode>GOVERNANCE</Mode><Days>30</Days></DefaultRetention></Rule></ObjectLockConfiguration>`))
+	item := newSRBucketObjectLockMeta(bucketName, &config, UTCNow().Add(time.Hour))
+	rec := applySRBucketMetaViaAdmin(t, credentials, item)
+	if rec.Code != http.StatusOK {
+		t.Fatalf("%s: admin Object Lock apply returned %d: %s", instanceType, rec.Code, rec.Body.String())
+	}
+	meta, err := globalBucketMetadataSys.Get(bucketName)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if meta.objectLockConfig == nil || len(meta.VersioningConfigXML) != 0 {
+		t.Fatalf("%s: unlocked bucket metadata = objectLock:%v versioning:%q", instanceType, meta.objectLockConfig, meta.VersioningConfigXML)
+	}
+}
+
+func TestHealObjectLockMetadataUsesObjectLockField(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testHealObjectLockMetadataUsesObjectLockField,
+	})
+}
+
+func testHealObjectLockMetadataUsesObjectLockField(obj ObjectLayer, instanceType, bucketName string,
+	_ http.Handler, credentials auth.Credentials, t *testing.T,
+) {
+	ctx := t.Context()
+	localID := globalDeploymentID()
+	remoteID := "remote-object-lock-heal"
+	updatedAt := UTCNow().Add(time.Hour)
+	createdAt := updatedAt.Add(-time.Hour)
+	config := base64.StdEncoding.EncodeToString([]byte(`<ObjectLockConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><ObjectLockEnabled>Enabled</ObjectLockEnabled><Rule><DefaultRetention><Mode>GOVERNANCE</Mode><Days>30</Days></DefaultRetention></Rule></ObjectLockConfiguration>`))
+
+	remoteApplies := make(chan madmin.SRBucketMeta, 1)
+	remote := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		var applied madmin.SRBucketMeta
+		if err := json.NewDecoder(r.Body).Decode(&applied); err != nil {
+			t.Errorf("%s: decode remote apply: %v", instanceType, err)
+			w.WriteHeader(http.StatusBadRequest)
+			return
+		}
+		remoteApplies <- applied
+		w.WriteHeader(http.StatusOK)
+	}))
+	defer remote.Close()
+
+	serviceCred, err := auth.CreateCredentials("object-lock-heal-svc", "object-lock-heal-service-secret")
+	if err != nil {
+		t.Fatal(err)
+	}
+	serviceCred.ParentUser = credentials.AccessKey
+	if _, err = globalIAMSys.store.AddServiceAccount(ctx, serviceCred); err != nil {
+		t.Fatal(err)
+	}
+	defer globalIAMSys.DeleteServiceAccount(ctx, serviceCred.AccessKey, false)
+
+	globalSiteReplicationSys.Lock()
+	oldEnabled := globalSiteReplicationSys.enabled
+	oldState := globalSiteReplicationSys.state
+	globalSiteReplicationSys.enabled = true
+	globalSiteReplicationSys.state = srState{
+		Name:                    "object-lock-heal-test",
+		ServiceAccountAccessKey: serviceCred.AccessKey,
+		Peers: map[string]madmin.PeerInfo{
+			localID:  {Name: "local", DeploymentID: localID},
+			remoteID: {Name: "remote", DeploymentID: remoteID, Endpoint: remote.URL},
+		},
+	}
+	globalSiteReplicationSys.Unlock()
+	defer func() {
+		globalSiteReplicationSys.Lock()
+		globalSiteReplicationSys.enabled = oldEnabled
+		globalSiteReplicationSys.state = oldState
+		globalSiteReplicationSys.Unlock()
+	}()
+
+	status := srStatusInfo{
+		Sites: map[string]madmin.PeerInfo{
+			localID:  {Name: "local", DeploymentID: localID},
+			remoteID: {Name: "remote", DeploymentID: remoteID, Endpoint: remote.URL},
+		},
+		BucketStats: map[string]map[string]srBucketStatsSummary{
+			bucketName: {
+				localID: {
+					SRBucketStatsSummary: madmin.SRBucketStatsSummary{OLockConfigMismatch: true},
+					meta: srBucketMetaInfo{SRBucketInfo: madmin.SRBucketInfo{
+						Bucket:                    bucketName,
+						CreatedAt:                 createdAt,
+						ObjectLockConfig:          &config,
+						ObjectLockConfigUpdatedAt: updatedAt,
+					}, DeploymentID: localID},
+				},
+				remoteID: {
+					SRBucketStatsSummary: madmin.SRBucketStatsSummary{OLockConfigMismatch: true},
+					meta: srBucketMetaInfo{SRBucketInfo: madmin.SRBucketInfo{
+						Bucket:    bucketName,
+						CreatedAt: createdAt,
+					}, DeploymentID: remoteID},
+				},
+			},
+		},
+	}
+	if err := globalSiteReplicationSys.healOLockConfigMetadata(ctx, obj, bucketName, status); err != nil {
+		t.Fatal(err)
+	}
+	select {
+	case applied := <-remoteApplies:
+		if applied.Type != madmin.SRBucketMetaTypeObjectLockConfig || applied.Bucket != bucketName ||
+			applied.ObjectLockConfig == nil || *applied.ObjectLockConfig != config || applied.Tags != nil || !applied.UpdatedAt.Equal(updatedAt) {
+			t.Fatalf("%s: remote heal apply = %#v", instanceType, applied)
+		}
+	case <-time.After(5 * time.Second):
+		t.Fatalf("%s: remote heal did not dispatch Object Lock metadata", instanceType)
+	}
+}
diff --git a/cmd/site-replication-status-accounting_test.go b/cmd/site-replication-status-accounting_test.go
new file mode 100644
index 000000000..ff4deeef1
--- /dev/null
+++ b/cmd/site-replication-status-accounting_test.go
@@ -0,0 +1,191 @@
+// Copyright (c) 2015-2026 MinIO, Inc.
+//
+// This file is part of MinIO Object Storage stack
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package cmd
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/minio/madmin-go/v3"
+	"github.com/minio/minio/internal/auth"
+)
+
+func TestSiteReplicationStatusAccountsPerSiteAndSurvivesMalformedConfig(t *testing.T) {
+	defer DetectTestLeak(t)()
+	ExecObjectLayerAPITest(ExecObjectLayerAPITestArgs{
+		t:          t,
+		objAPITest: testSiteReplicationStatusAccountsPerSiteAndSurvivesMalformedConfig,
+	})
+}
+
+func testSiteReplicationStatusAccountsPerSiteAndSurvivesMalformedConfig(obj ObjectLayer, instanceType, localBucket string,
+	_ http.Handler, credentials auth.Credentials, t *testing.T,
+) {
+	ctx := t.Context()
+	remoteBucket := getRandomBucketName()
+	if err := obj.MakeBucket(ctx, remoteBucket, MakeBucketOptions{}); err != nil {
+		t.Fatal(err)
+	}
+	remoteBucketMeta, err := loadBucketMetadata(ctx, obj, remoteBucket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	globalBucketMetadataSys.Set(remoteBucket, remoteBucketMeta)
+	globalNotificationSys.LoadBucketMetadata(ctx, remoteBucket)
+
+	tagXML := []byte(`<Tagging><TagSet><Tag><Key>key</Key><Value>value</Value></Tag></TagSet></Tagging>`)
+	versioningXML := []byte(`<VersioningConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><Status>Enabled</Status></VersioningConfiguration>`)
+	objectLockXML := []byte(`<ObjectLockConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><ObjectLockEnabled>Enabled</ObjectLockEnabled><Rule><DefaultRetention><Mode>GOVERNANCE</Mode><Days>30</Days></DefaultRetention></Rule></ObjectLockConfiguration>`)
+	sseXML := []byte(`<ServerSideEncryptionConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/"><Rule><ApplyServerSideEncryptionByDefault><SSEAlgorithm>AES256</SSEAlgorithm></ApplyServerSideEncryptionByDefault></Rule></ServerSideEncryptionConfiguration>`)
+	quotaJSON, err := json.Marshal(madmin.BucketQuota{Type: madmin.HardQuota, Quota: 1024})
+	if err != nil {
+		t.Fatal(err)
+	}
+	policyJSON := []byte(fmt.Sprintf(`{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":["*"]},"Action":["s3:GetObject"],"Resource":["arn:aws:s3:::%s/*"]}]}`, localBucket))
+
+	for configFile, data := range map[string][]byte{
+		bucketTaggingConfig:    tagXML,
+		bucketVersioningConfig: versioningXML,
+		objectLockConfig:       objectLockXML,
+		bucketSSEConfig:        sseXML,
+		bucketQuotaConfigFile:  quotaJSON,
+		bucketPolicyConfig:     policyJSON,
+		bucketCorsConfig:       []byte(testSiteReplicationCORSDoc),
+	} {
+		if _, err := globalBucketMetadataSys.Update(ctx, localBucket, configFile, data); err != nil {
+			t.Fatalf("%s: update %s: %v", instanceType, configFile, err)
+		}
+	}
+
+	encode := func(data []byte) *string {
+		encoded := base64.StdEncoding.EncodeToString(data)
+		return &encoded
+	}
+	remotePolicy := []byte(fmt.Sprintf(`{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Principal":{"AWS":["*"]},"Action":["s3:GetObject"],"Resource":["arn:aws:s3:::%s/*"]}]}`, remoteBucket))
+	localMeta, err := globalBucketMetadataSys.Get(localBucket)
+	if err != nil {
+		t.Fatal(err)
+	}
+	remoteInfo := madmin.SRInfo{
+		DeploymentID: "remote-status-accounting",
+		Buckets: map[string]madmin.SRBucketInfo{
+			localBucket: {
+				Bucket:    localBucket,
+				CreatedAt: localMeta.Created,
+			},
+			remoteBucket: {
+				Bucket:           remoteBucket,
+				CreatedAt:        remoteBucketMeta.Created,
+				Tags:             encode(tagXML),
+				Versioning:       encode(versioningXML),
+				ObjectLockConfig: encode(objectLockXML),
+				SSEConfig:        encode(sseXML),
+				QuotaConfig:      encode(quotaJSON),
+				Policy:           remotePolicy,
+				CorsConfig:       encode([]byte(testSiteReplicationCORSDoc)),
+			},
+		},
+	}
+	remote := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.Header().Set("Content-Type", "application/json")
+		if err := json.NewEncoder(w).Encode(remoteInfo); err != nil {
+			t.Errorf("%s: encode remote metadata: %v", instanceType, err)
+		}
+	}))
+	defer remote.Close()
+
+	serviceCred, err := auth.CreateCredentials("status-accounting-svc", "status-accounting-service-secret")
+	if err != nil {
+		t.Fatal(err)
+	}
+	serviceCred.ParentUser = credentials.AccessKey
+	if _, err = globalIAMSys.store.AddServiceAccount(ctx, serviceCred); err != nil {
+		t.Fatal(err)
+	}
+	defer globalIAMSys.DeleteServiceAccount(ctx, serviceCred.AccessKey, false)
+
+	localID := globalDeploymentID()
+	remoteID := remoteInfo.DeploymentID
+	globalSiteReplicationSys.Lock()
+	oldEnabled := globalSiteReplicationSys.enabled
+	oldState := globalSiteReplicationSys.state
+	globalSiteReplicationSys.enabled = true
+	globalSiteReplicationSys.state = srState{
+		Name:                    "status-accounting-test",
+		ServiceAccountAccessKey: serviceCred.AccessKey,
+		Peers: map[string]madmin.PeerInfo{
+			localID:  {Name: "local", DeploymentID: localID},
+			remoteID: {Name: "remote", DeploymentID: remoteID, Endpoint: remote.URL},
+		},
+	}
+	globalSiteReplicationSys.Unlock()
+	defer func() {
+		globalSiteReplicationSys.Lock()
+		globalSiteReplicationSys.enabled = oldEnabled
+		globalSiteReplicationSys.state = oldState
+		globalSiteReplicationSys.Unlock()
+	}()
+
+	check := func(name string, wantRemoteTags, wantRemoteQuota int) {
+		t.Helper()
+		status, err := globalSiteReplicationSys.siteReplicationStatus(ctx, obj, madmin.SRStatusOptions{Buckets: true})
+		if err != nil {
+			t.Fatal(err)
+		}
+		local := status.StatsSummary[localID]
+		remote := status.StatsSummary[remoteID]
+		if local.TotalBucketsCount != 2 || remote.TotalBucketsCount != 2 {
+			t.Fatalf("%s: bucket totals = local:%d remote:%d", name, local.TotalBucketsCount, remote.TotalBucketsCount)
+		}
+		if local.TotalTagsCount != 1 || remote.TotalTagsCount != wantRemoteTags ||
+			local.TotalLockConfigCount != 1 || remote.TotalLockConfigCount != 1 ||
+			local.TotalSSEConfigCount != 1 || remote.TotalSSEConfigCount != 1 ||
+			local.TotalVersioningConfigCount != 1 || remote.TotalVersioningConfigCount != 1 ||
+			local.TotalBucketPoliciesCount != 1 || remote.TotalBucketPoliciesCount != 1 ||
+			local.TotalQuotaConfigCount != 1 || remote.TotalQuotaConfigCount != wantRemoteQuota ||
+			local.TotalCorsConfigCount != 1 || remote.TotalCorsConfigCount != 1 {
+			t.Fatalf("%s: site totals = local:%+v remote:%+v", name, local, remote)
+		}
+		if local.ReplicatedTags != 0 || remote.ReplicatedTags != 0 ||
+			local.ReplicatedBucketPolicies != 0 || remote.ReplicatedBucketPolicies != 0 ||
+			local.ReplicatedQuotaConfig != 0 || remote.ReplicatedQuotaConfig != 0 {
+			t.Fatalf("%s: asymmetric configs counted as replicated: local:%+v remote:%+v", name, local, remote)
+		}
+		remoteBucketStatus := status.BucketStats[remoteBucket][remoteID]
+		if remoteBucketStatus.HasTagsSet != (wantRemoteTags != 0) || remoteBucketStatus.HasQuotaCfgSet != (wantRemoteQuota != 0) {
+			t.Fatalf("%s: remote bucket presence = tags:%v quota:%v", name, remoteBucketStatus.HasTagsSet, remoteBucketStatus.HasQuotaCfgSet)
+		}
+	}
+
+	check("valid asymmetric configs", 1, 1)
+	invalidTags := "not-base64"
+	info := remoteInfo.Buckets[remoteBucket]
+	info.Tags = &invalidTags
+	remoteInfo.Buckets[remoteBucket] = info
+	check("malformed tags do not drop site", 0, 1)
+
+	emptyQuota := base64.StdEncoding.EncodeToString([]byte(`{}`))
+	info = remoteInfo.Buckets[remoteBucket]
+	info.QuotaConfig = &emptyQuota
+	remoteInfo.Buckets[remoteBucket] = info
+	check("empty quota is absent", 0, 0)
+}
diff --git a/cmd/site-replication.go b/cmd/site-replication.go
index 41f0eb512..31232fc4d 100644
--- a/cmd/site-replication.go
+++ b/cmd/site-replication.go
@@ -46,6 +46,7 @@ import (
 	"github.com/minio/minio/internal/bucket/cors"
 	"github.com/minio/minio/internal/bucket/lifecycle"
 	sreplication "github.com/minio/minio/internal/bucket/replication"
+	"github.com/minio/minio/internal/bucket/versioning"
 	"github.com/minio/minio/internal/logger"
 	xldap "github.com/minio/pkg/v3/ldap"
 	"github.com/minio/pkg/v3/policy"
@@ -888,6 +889,32 @@ func (c *SiteReplicationSys) DeleteBucketHook(ctx context.Context, bucket string
 	return errors.Unwrap(cerr)
 }
 
+func enablePeerBucketVersioning(meta *BucketMetadata) error {
+	if len(meta.VersioningConfigXML) == 0 {
+		meta.VersioningConfigXML = enabledBucketVersioningConfig
+		if meta.VersioningConfigUpdatedAt.IsZero() {
+			meta.VersioningConfigUpdatedAt = meta.Created
+		}
+		return nil
+	}
+	config, err := versioning.ParseConfig(bytes.NewReader(meta.VersioningConfigXML))
+	if err != nil {
+		meta.VersioningConfigXML = enabledBucketVersioningConfig
+		meta.VersioningConfigUpdatedAt = UTCNow()
+		return nil
+	}
+	if config.Enabled() {
+		return nil
+	}
+	config.Status = versioning.Enabled
+	meta.VersioningConfigXML, err = xml.Marshal(config)
+	if err != nil {
+		return err
+	}
+	meta.VersioningConfigUpdatedAt = UTCNow()
+	return nil
+}
+
 // PeerBucketMakeWithVersioningHandler - creates bucket and enables versioning.
 func (c *SiteReplicationSys) PeerBucketMakeWithVersioningHandler(ctx context.Context, bucket string, opts MakeBucketOptions) error {
 	objAPI := newObjectLayerFn()
@@ -916,9 +943,14 @@ func (c *SiteReplicationSys) PeerBucketMakeWithVersioningHandler(ctx context.Con
 
 	meta.SetCreatedAt(opts.CreatedAt)
 
-	meta.VersioningConfigXML = enabledBucketVersioningConfig
-	if opts.LockEnabled {
+	if err := enablePeerBucketVersioning(&meta); err != nil {
+		return wrapSRErr(err)
+	}
+	if opts.LockEnabled && len(meta.ObjectLockConfigXML) == 0 {
 		meta.ObjectLockConfigXML = enabledBucketObjectLockConfig
+		if meta.ObjectLockConfigUpdatedAt.IsZero() {
+			meta.ObjectLockConfigUpdatedAt = meta.Created
+		}
 	}
 
 	if err := meta.Save(context.Background(), objAPI); err != nil {
@@ -1727,6 +1759,26 @@ func (c *SiteReplicationSys) PeerBucketTaggingHandler(ctx context.Context, bucke
 	return nil
 }
 
+func newSRBucketObjectLockMeta(bucket string, config *string, updatedAt time.Time) madmin.SRBucketMeta {
+	return madmin.SRBucketMeta{
+		Type:             madmin.SRBucketMetaTypeObjectLockConfig,
+		Bucket:           bucket,
+		ObjectLockConfig: config,
+		UpdatedAt:        updatedAt,
+	}
+}
+
+func srObjectLockPayload(item madmin.SRBucketMeta) *string {
+	if item.ObjectLockConfig != nil {
+		return item.ObjectLockConfig
+	}
+	return item.Tags
+}
+
+func (c *SiteReplicationSys) peerBucketObjectLockConfigItem(ctx context.Context, item madmin.SRBucketMeta) error {
+	return c.PeerBucketObjectLockConfigHandler(ctx, item.Bucket, srObjectLockPayload(item), item.UpdatedAt)
+}
+
 // PeerBucketObjectLockConfigHandler - sets object lock on local bucket.
 func (c *SiteReplicationSys) PeerBucketObjectLockConfigHandler(ctx context.Context, bucket string, objectLockData *string, updatedAt time.Time) error {
 	if objectLockData != nil {
@@ -2176,12 +2228,7 @@ func (c *SiteReplicationSys) syncToAllPeers(ctx context.Context, addOpts madmin.
 		objLockCfgData, tm := meta.ObjectLockConfigXML, meta.ObjectLockConfigUpdatedAt
 		if len(objLockCfgData) > 0 {
 			objLockStr := base64.StdEncoding.EncodeToString(objLockCfgData)
-			err = c.BucketMetaHook(ctx, madmin.SRBucketMeta{
-				Type:      madmin.SRBucketMetaTypeObjectLockConfig,
-				Bucket:    bucket,
-				Tags:      &objLockStr,
-				UpdatedAt: tm,
-			})
+			err = c.BucketMetaHook(ctx, newSRBucketObjectLockMeta(bucket, &objLockStr, tm))
 			if err != nil {
 				return errSRBucketMetaError(err)
 			}
@@ -3406,80 +3453,116 @@ func (c *SiteReplicationSys) siteReplicationStatus(ctx context.Context, objAPI O
 			quotaCfgs := make([]*madmin.BucketQuota, numSites)
 			sseCfgSet := set.NewStringSet()
 			versionCfgSet := set.NewStringSet()
-			var tagCount, olockCfgCount, sseCfgCount, corsCfgCount, versionCfgCount int
+			validReplCfg := make([]bool, numSites)
+			validVersionCfg := make([]bool, numSites)
+			validQuotaCfg := make([]bool, numSites)
+			validTags := make([]bool, numSites)
+			validPolicies := make([]bool, numSites)
+			validObjectLockCfg := make([]bool, numSites)
+			validSSECfg := make([]bool, numSites)
+			validCorsCfg := make([]bool, numSites)
+			var tagCount, olockCfgCount, policyCount, quotaCfgCount, sseCfgCount, corsCfgCount, versionCfgCount int
 			for i, s := range slc {
+				logInvalid := func(configType string, err error) {
+					replLogOnceIf(ctx,
+						fmt.Errorf("unable to parse %s metadata for bucket %s from site %s: %w", configType, b, s.DeploymentID, err),
+						"site-replication-status-"+configType+"-"+b+"-"+s.DeploymentID)
+				}
 				if s.ReplicationConfig != nil {
 					cfgBytes, err := base64.StdEncoding.DecodeString(*s.ReplicationConfig)
-					if err != nil {
-						continue
+					if err == nil {
+						cfg, err := sreplication.ParseConfig(bytes.NewReader(cfgBytes))
+						if err == nil {
+							replCfgs[i] = cfg
+							validReplCfg[i] = true
+						} else {
+							logInvalid("replication", err)
+						}
+					} else {
+						logInvalid("replication", err)
 					}
-					cfg, err := sreplication.ParseConfig(bytes.NewReader(cfgBytes))
-					if err != nil {
-						continue
-					}
-					replCfgs[i] = cfg
 				}
 				if s.Versioning != nil {
 					configData, err := base64.StdEncoding.DecodeString(*s.Versioning)
-					if err != nil {
-						continue
-					}
-					versionCfgCount++
-					if !versionCfgSet.Contains(string(configData)) {
-						versionCfgSet.Add(string(configData))
+					if err == nil {
+						validVersionCfg[i] = true
+						versionCfgCount++
+						if !versionCfgSet.Contains(string(configData)) {
+							versionCfgSet.Add(string(configData))
+						}
+					} else {
+						logInvalid("versioning", err)
 					}
 				}
 				if s.QuotaConfig != nil {
 					cfgBytes, err := base64.StdEncoding.DecodeString(*s.QuotaConfig)
-					if err != nil {
-						continue
+					if err == nil {
+						cfg, err := parseBucketQuota(b, cfgBytes)
+						if err == nil {
+							if cfg != nil && *cfg != (madmin.BucketQuota{}) {
+								quotaCfgs[i] = cfg
+								validQuotaCfg[i] = true
+								quotaCfgCount++
+							}
+						} else {
+							logInvalid("quota", err)
+						}
+					} else {
+						logInvalid("quota", err)
 					}
-					cfg, err := parseBucketQuota(b, cfgBytes)
-					if err != nil {
-						continue
-					}
-					quotaCfgs[i] = cfg
 				}
 				if s.Tags != nil {
 					tagBytes, err := base64.StdEncoding.DecodeString(*s.Tags)
-					if err != nil {
-						continue
-					}
-					tagCount++
-					if !tagSet.Contains(string(tagBytes)) {
-						tagSet.Add(string(tagBytes))
+					if err == nil {
+						validTags[i] = true
+						tagCount++
+						if !tagSet.Contains(string(tagBytes)) {
+							tagSet.Add(string(tagBytes))
+						}
+					} else {
+						logInvalid("tags", err)
 					}
 				}
 				if len(s.Policy) > 0 {
 					plcy, err := policy.ParseBucketPolicyConfig(bytes.NewReader(s.Policy), b)
-					if err != nil {
-						continue
+					if err == nil {
+						policies[i] = plcy
+						validPolicies[i] = true
+						policyCount++
+					} else {
+						logInvalid("policy", err)
 					}
-					policies[i] = plcy
 				}
 				if s.ObjectLockConfig != nil {
 					configData, err := base64.StdEncoding.DecodeString(*s.ObjectLockConfig)
-					if err != nil {
-						continue
-					}
-					olockCfgCount++
-					if !olockConfigSet.Contains(string(configData)) {
-						olockConfigSet.Add(string(configData))
+					if err == nil {
+						validObjectLockCfg[i] = true
+						olockCfgCount++
+						if !olockConfigSet.Contains(string(configData)) {
+							olockConfigSet.Add(string(configData))
+						}
+					} else {
+						logInvalid("object-lock", err)
 					}
 				}
 				if s.SSEConfig != nil {
 					configData, err := base64.StdEncoding.DecodeString(*s.SSEConfig)
-					if err != nil {
-						continue
-					}
-					sseCfgCount++
-					if !sseCfgSet.Contains(string(configData)) {
-						sseCfgSet.Add(string(configData))
+					if err == nil {
+						validSSECfg[i] = true
+						sseCfgCount++
+						if !sseCfgSet.Contains(string(configData)) {
+							sseCfgSet.Add(string(configData))
+						}
+					} else {
+						logInvalid("sse", err)
 					}
 				}
 				if s.CorsConfig != nil {
 					if _, err := decodeCORSReplicationPayload(s.CorsConfig); err == nil {
+						validCorsCfg[i] = true
 						corsCfgCount++
+					} else {
+						logInvalid("cors", err)
 					}
 				}
 				ss, ok := info.StatsSummary[s.DeploymentID]
@@ -3491,24 +3574,27 @@ func (c *SiteReplicationSys) siteReplicationStatus(ctx context.Context, objAPI O
 					ss.ReplicatedBuckets++
 				}
 				ss.TotalBucketsCount++
-				if tagCount > 0 {
+				if validTags[i] {
 					ss.TotalTagsCount++
 				}
-				if olockCfgCount > 0 {
+				if validObjectLockCfg[i] {
 					ss.TotalLockConfigCount++
 				}
-				if sseCfgCount > 0 {
+				if validSSECfg[i] {
 					ss.TotalSSEConfigCount++
 				}
-				if s.CorsConfig != nil {
+				if validCorsCfg[i] {
 					ss.TotalCorsConfigCount++
 				}
-				if versionCfgCount > 0 {
+				if validVersionCfg[i] {
 					ss.TotalVersioningConfigCount++
 				}
-				if len(policies) > 0 {
+				if validPolicies[i] {
 					ss.TotalBucketPoliciesCount++
 				}
+				if validQuotaCfg[i] {
+					ss.TotalQuotaConfigCount++
+				}
 				info.StatsSummary[s.DeploymentID] = ss
 			}
 			tagMismatch := !isReplicated(tagCount, numSites, tagSet)
@@ -3542,13 +3628,13 @@ func (c *SiteReplicationSys) siteReplicationStatus(ctx context.Context, objAPI O
 					PolicyMismatch:           policyMismatch,
 					ReplicationCfgMismatch:   replCfgMismatch,
 					QuotaCfgMismatch:         quotaCfgMismatch,
-					HasReplicationCfg:        s.ReplicationConfig != nil,
-					HasTagsSet:               s.Tags != nil,
-					HasOLockConfigSet:        s.ObjectLockConfig != nil,
-					HasPolicySet:             s.Policy != nil,
+					HasReplicationCfg:        validReplCfg[i],
+					HasTagsSet:               validTags[i],
+					HasOLockConfigSet:        validObjectLockCfg[i],
+					HasPolicySet:             validPolicies[i],
 					HasQuotaCfgSet:           quotaCfgSet,
-					HasSSECfgSet:             s.SSEConfig != nil,
-					HasCorsCfgSet:            s.CorsConfig != nil,
+					HasSSECfgSet:             validSSECfg[i],
+					HasCorsCfgSet:            validCorsCfg[i],
 				}
 				var m srBucketMetaInfo
 				if len(bucketStats[s.Bucket]) > dIdx {
@@ -3574,12 +3660,15 @@ func (c *SiteReplicationSys) siteReplicationStatus(ctx context.Context, objAPI O
 				if !corsCfgMismatch && corsCfgCount == numSites {
 					sum.ReplicatedCorsConfig++
 				}
-				if !policyMismatch && len(policies) == numSites {
+				if !policyMismatch && policyCount == numSites {
 					sum.ReplicatedBucketPolicies++
 				}
 				if !tagMismatch && tagCount == numSites {
 					sum.ReplicatedTags++
 				}
+				if !quotaCfgMismatch && quotaCfgCount == numSites {
+					sum.ReplicatedQuotaConfig++
+				}
 				info.StatsSummary[s.DeploymentID] = sum
 			}
 		}
@@ -5322,12 +5411,7 @@ func (c *SiteReplicationSys) healOLockConfigMetadata(ctx context.Context, objAPI
 			return wrapSRErr(err)
 		}
 		peerName := info.Sites[dID].Name
-		err = admClient.SRPeerReplicateBucketMeta(ctx, madmin.SRBucketMeta{
-			Type:      madmin.SRBucketMetaTypeObjectLockConfig,
-			Bucket:    bucket,
-			Tags:      latestObjLockConfig,
-			UpdatedAt: lastUpdate,
-		})
+		err = admClient.SRPeerReplicateBucketMeta(ctx, newSRBucketObjectLockMeta(bucket, latestObjLockConfig, lastUpdate))
 		if err != nil {
 			replLogIf(ctx, c.annotatePeerErr(peerName, replicateBucketMetadata,
 				fmt.Errorf("Unable to heal object lock config metadata for peer %s from peer %s : %w",
diff --git a/internal/hash/checksum.go b/internal/hash/checksum.go
index 5131087b8..e4ced2fba 100644
--- a/internal/hash/checksum.go
+++ b/internal/hash/checksum.go
@@ -157,7 +157,6 @@ func ChecksumStringToType(alg string) ChecksumType {
 	case "SHA256":
 		return ChecksumSHA256
 	case "CRC64NVME":
-		// AWS seems to ignore full value, and just assume it.
 		return ChecksumCRC64NVME
 	case "":
 		return ChecksumNone
@@ -192,7 +191,9 @@ func NewChecksumType(alg, objType string) ChecksumType {
 		}
 		return ChecksumSHA256
 	case "CRC64NVME":
-		// AWS seems to ignore full value, and just assume it.
+		if objType == xhttp.AmzChecksumTypeComposite {
+			return ChecksumInvalid
+		}
 		return ChecksumCRC64NVME
 	case "":
 		if full != 0 {
@@ -657,22 +658,55 @@ func AddChecksumHeader(w http.ResponseWriter, c map[string]string) {
 	}
 }
 
+func isSupportedChecksumHeader(name string) bool {
+	switch {
+	case strings.EqualFold(name, xhttp.AmzChecksumAlgo),
+		strings.EqualFold(name, xhttp.AmzChecksumType),
+		strings.EqualFold(name, xhttp.AmzChecksumMode):
+		return true
+	}
+	for _, checksumType := range BaseChecksumTypes {
+		if strings.EqualFold(name, checksumType.Key()) {
+			return true
+		}
+	}
+	return false
+}
+
+func hasUnsupportedChecksumHeader(h http.Header) bool {
+	for name := range h {
+		if strings.HasPrefix(strings.ToLower(name), "x-amz-checksum-") && !isSupportedChecksumHeader(name) {
+			return true
+		}
+	}
+	return false
+}
+
 // GetContentChecksum returns content checksum.
 // Returns ErrInvalidChecksum if so.
 // Returns nil, nil if no checksum.
 func GetContentChecksum(h http.Header) (*Checksum, error) {
+	if hasUnsupportedChecksumHeader(h) {
+		return nil, ErrInvalidChecksum
+	}
 	if trailing := h.Values(xhttp.AmzTrailer); len(trailing) > 0 {
 		var res *Checksum
-		for _, header := range trailing {
-			var duplicates bool
-			for _, t := range BaseChecksumTypes {
-				if strings.EqualFold(t.Key(), header) {
-					duplicates = res != nil
-					res = NewChecksumWithType(t|ChecksumTrailing, "")
+		for _, headers := range trailing {
+			for header := range strings.SplitSeq(headers, ",") {
+				header = strings.TrimSpace(header)
+				var duplicates bool
+				for _, t := range BaseChecksumTypes {
+					if strings.EqualFold(t.Key(), header) {
+						duplicates = res != nil
+						res = NewChecksumWithType(t|ChecksumTrailing, "")
+					}
+				}
+				if strings.HasPrefix(strings.ToLower(header), "x-amz-checksum-") && !isSupportedChecksumHeader(header) {
+					return nil, ErrInvalidChecksum
+				}
+				if duplicates {
+					return nil, ErrInvalidChecksum
 				}
-			}
-			if duplicates {
-				return nil, ErrInvalidChecksum
 			}
 		}
 		if res != nil {
@@ -682,7 +716,11 @@ func GetContentChecksum(h http.Header) (*Checksum, error) {
 					return nil, ErrInvalidChecksum
 				}
 				res.Type |= ChecksumFullObject
-			case xhttp.AmzChecksumTypeComposite, "":
+			case xhttp.AmzChecksumTypeComposite:
+				if res.Type.Base().Is(ChecksumCRC64NVME) {
+					return nil, ErrInvalidChecksum
+				}
+			case "":
 			default:
 				return nil, ErrInvalidChecksum
 			}
@@ -748,5 +786,8 @@ func getContentChecksum(h http.Header) (t ChecksumType, s string) {
 	for _, t := range BaseChecksumTypes {
 		checkType(t)
 	}
+	if t.Base().Is(ChecksumCRC64NVME) && h.Get(xhttp.AmzChecksumType) == xhttp.AmzChecksumTypeComposite {
+		return ChecksumInvalid, ""
+	}
 	return t, s
 }
diff --git a/internal/hash/checksum_test.go b/internal/hash/checksum_test.go
index 504803795..595302818 100644
--- a/internal/hash/checksum_test.go
+++ b/internal/hash/checksum_test.go
@@ -18,14 +18,58 @@
 package hash
 
 import (
+	"errors"
+	"net/http"
 	"net/http/httptest"
 	"testing"
 
 	xhttp "github.com/minio/minio/internal/http"
 )
 
+func TestGetContentChecksumRejectsUnsupportedHeaders(t *testing.T) {
+	unsupported := []string{
+		"x-amz-checksum-md5",
+		"x-amz-checksum-sha512",
+		"x-amz-checksum-xxhash64",
+		"x-amz-checksum-xxhash3",
+		"x-amz-checksum-xxhash128",
+		"x-amz-checksum-future",
+	}
+	for _, header := range unsupported {
+		t.Run("header/"+header, func(t *testing.T) {
+			h := http.Header{header: {"AA=="}}
+			if _, err := GetContentChecksum(h); !errors.Is(err, ErrInvalidChecksum) {
+				t.Fatalf("GetContentChecksum(%s) error = %v, want ErrInvalidChecksum", header, err)
+			}
+		})
+		t.Run("trailer/"+header, func(t *testing.T) {
+			h := http.Header{xhttp.AmzTrailer: {header}}
+			if _, err := GetContentChecksum(h); !errors.Is(err, ErrInvalidChecksum) {
+				t.Fatalf("GetContentChecksum(trailer %s) error = %v, want ErrInvalidChecksum", header, err)
+			}
+		})
+	}
+
+	for header, value := range map[string]string{
+		xhttp.AmzChecksumAlgo:          "CRC32",
+		xhttp.AmzChecksumType:          xhttp.AmzChecksumTypeComposite,
+		xhttp.AmzChecksumMode:          "ENABLED",
+		"x-amz-sdk-checksum-algorithm": "SHA512",
+	} {
+		t.Run("control/"+header, func(t *testing.T) {
+			h := http.Header{header: {value}}
+			if _, err := GetContentChecksum(h); errors.Is(err, ErrInvalidChecksum) {
+				t.Fatalf("control header %s was rejected", header)
+			}
+		})
+	}
+}
+
 // TestChecksumAddToHeader tests that adding and retrieving a checksum on a header works
 func TestChecksumAddToHeader(t *testing.T) {
+	if got := NewChecksumType("CRC64NVME", xhttp.AmzChecksumTypeComposite); !got.Is(ChecksumInvalid) {
+		t.Fatalf("CRC64NVME/COMPOSITE = %s, want invalid", got.StringFull())
+	}
 	tests := []struct {
 		name     string
 		checksum ChecksumType
@@ -106,6 +150,16 @@ func TestChecksumAddToHeader(t *testing.T) {
 	}
 }
 
+func TestCRC64NVMECompositeTrailerIsInvalid(t *testing.T) {
+	h := http.Header{}
+	h.Set(xhttp.AmzTrailer, ChecksumCRC64NVME.Key())
+	h.Set(xhttp.AmzChecksumType, xhttp.AmzChecksumTypeComposite)
+	_, err := GetContentChecksum(h)
+	if !errors.Is(err, ErrInvalidChecksum) {
+		t.Fatalf("CRC64NVME/COMPOSITE trailer error = %v, want ErrInvalidChecksum", err)
+	}
+}
+
 // TestChecksumSerializeDeserialize checks AppendTo can be reversed by ChecksumFromBytes
 func TestChecksumSerializeDeserialize(t *testing.T) {
 	myData := []byte("this-is-a-checksum-data-test")