diff --git a/docs/release-control/v6/internal/subsystems/deployment-installability.md b/docs/release-control/v6/internal/subsystems/deployment-installability.md
index 9d8a2c376..c5348271f 100644
--- a/docs/release-control/v6/internal/subsystems/deployment-installability.md
+++ b/docs/release-control/v6/internal/subsystems/deployment-installability.md
@@ -5019,7 +5019,14 @@ back to a marker-free draft.
 
 `scripts/verify-github-release-integrity.sh` is the shared post-publication
 check. It binds the release database ID, tag, exact source SHA, immutable state,
-and single digest-bearing activation marker, then requires `gh release verify`
+and single digest-bearing activation marker. Uniqueness counts every asset named
+`release-activation.json`, including pending, empty, or malformed entries,
+before validating the marker's metadata. Duplicate names must fail before
+attestation or download; filtering out invalid entries must not make an
+ambiguous inventory acceptable. The regression cases in
+`scripts/release_control/verify_github_release_integrity_test.py` cover both
+valid duplicates and a valid marker accompanied by a malformed duplicate.
+The check then requires `gh release verify`
 to validate GitHub's signed release attestation. It must then download the
 activation marker from that release and require `gh release verify-asset` to
 bind the exact consumed bytes to the signed release attestation. Filename,
diff --git a/scripts/release_control/verify_github_release_integrity_test.py b/scripts/release_control/verify_github_release_integrity_test.py
index c6a485d96..61b70fd1a 100644
--- a/scripts/release_control/verify_github_release_integrity_test.py
+++ b/scripts/release_control/verify_github_release_integrity_test.py
@@ -230,6 +230,22 @@ class VerifyGitHubReleaseIntegrityTest(unittest.TestCase):
         self.assertNotEqual(result.returncode, 0)
         self.assertIn("activation marker", result.stderr)
 
+    def test_rejects_duplicate_activation_names_before_attestation(self) -> None:
+        for duplicate in (
+            {"state": "uploaded", "size": 300, "digest": "sha256:" + "b" * 64},
+            {"state": "new", "size": 0, "digest": None},
+        ):
+            with self.subTest(duplicate=duplicate):
+                release = self.release()
+                release["assets"].append(
+                    {"name": "release-activation.json", **duplicate}
+                )
+                result, calls = self.run_verifier(release)
+                self.assertNotEqual(result.returncode, 0)
+                self.assertIn("activation marker", result.stderr)
+                self.assertNotIn("release verify", calls)
+                self.assertNotIn("release download", calls)
+
     def test_rejects_failed_release_attestation(self) -> None:
         result, _ = self.run_verifier(self.release(), verification_succeeds=False)
         self.assertNotEqual(result.returncode, 0)
diff --git a/scripts/verify-github-release-integrity.sh b/scripts/verify-github-release-integrity.sh
index 75cf13acb..6fa4d3138 100755
--- a/scripts/verify-github-release-integrity.sh
+++ b/scripts/verify-github-release-integrity.sh
@@ -97,6 +97,7 @@ if ! jq -e \
      .immutable == true and
      ($expected_release_id == "" or (.id | tostring) == $expected_release_id) and
      ($expected_source_sha == "" or .target_commitish == $expected_source_sha) and
+     ([.assets[]? | select(.name == "release-activation.json")] | length == 1) and
      ([.assets[]? | select(
         .name == "release-activation.json" and
         .state == "uploaded" and