diff --git a/src/api/routes.ts b/src/api/routes.ts
index 75d25881fb..ba3d0e72c8 100644
--- a/src/api/routes.ts
+++ b/src/api/routes.ts
@@ -2272,7 +2272,7 @@ export function createApp() {
     if (gate instanceof Response) return gate;
     const body = await c.req.json().catch(() => null);
     if (body === null) return c.json({ error: "invalid_json" }, 400);
-    const manifest = await upsertRepoFocusManifest(c.env, fullName, body, "api_record");
+    const manifest = await upsertRepoFocusManifest(c.env, fullName, stripMaintainerFocusManifestSettings(body), "api_record");
     return c.json({ repoFullName: fullName, manifest, policy: compileFocusManifestPolicy(manifest) });
   });
 
@@ -5252,6 +5252,20 @@ const LINT_PR_TEXT_PATH = "/v1/lint/pr-text";
 const VALIDATE_FOCUS_MANIFEST_PATH = "/v1/validate/focus-manifest";
 const LINT_SLOP_RISK_PATH = "/v1/lint/slop-risk";
 const LINT_ISSUE_SLOP_PATH = "/v1/lint/issue-slop";
+function stripMaintainerFocusManifestSettings(raw: unknown): unknown {
+  // Split out from the rest of the guard below: this call site's only caller already 400s on a null body
+  // before ever reaching here, so this specific arm is unreachable in practice -- kept as defense-in-depth
+  // (typeof null === "object" in JS, so without it a null raw would fall through to the property access
+  // below and throw) for any future caller of this currently-unexported function.
+  /* v8 ignore next */
+  if (raw === null) return raw;
+  if (typeof raw !== "object" || Array.isArray(raw)) return raw;
+  const record = raw as Record<string, JsonValue>;
+  const settings = record.settings;
+  if (settings === null || typeof settings !== "object" || Array.isArray(settings) || !("agentGlobalFreezeOverride" in settings)) return raw;
+  const { agentGlobalFreezeOverride: _agentGlobalFreezeOverride, ...safeSettings } = settings;
+  return { ...record, settings: safeSettings };
+}
 // Contributor (miner) side of the extension (#556). Minted for NON-maintainer sign-ins; strictly
 // self-only — a token may only reach `/v1/extension/contributors/<self>/*`, enforced by the coarse
 // path check below plus `requireContributorAccess` (actor === login) in every handler.
diff --git a/test/unit/routes-focus-manifest.test.ts b/test/unit/routes-focus-manifest.test.ts
index 74aed49609..8d1b4a619a 100644
--- a/test/unit/routes-focus-manifest.test.ts
+++ b/test/unit/routes-focus-manifest.test.ts
@@ -1,8 +1,11 @@
 import { beforeEach, describe, expect, it, vi } from "vitest";
 import { createApp } from "../../src/api/routes";
 import { createSessionForGitHubUser } from "../../src/auth/security";
-import { upsertInstallation, upsertPullRequestFromGitHub, upsertRepositoryFromGitHub } from "../../src/db/repositories";
+import { isDbFrozenForRepo, setGlobalAgentFrozen, upsertInstallation, upsertPullRequestFromGitHub, upsertRepositoryFromGitHub } from "../../src/db/repositories";
 import { getRepositoryCollaboratorPermission } from "../../src/github/app";
+import { resolveEffectiveSettings } from "../../src/signals/focus-manifest";
+import type { FocusManifest } from "../../src/signals/focus-manifest";
+import type { RepositorySettings } from "../../src/types";
 import { createTestEnv } from "../helpers/d1";
 
 vi.mock("../../src/github/app", async (importOriginal) => ({
@@ -93,6 +96,67 @@ describe("focus-manifest route auth", () => {
     });
   });
 
+  it("strips operator-only freeze overrides from maintainer-writable focus-manifest updates", async () => {
+    const app = createApp();
+    const env = createTestEnv({ ADMIN_GITHUB_LOGINS: "" });
+    await seedRegisteredInstalledRepo(env, 201, "repo-owner", "owned-repo");
+    await setGlobalAgentFrozen(env, true, "operator");
+    mockedPermission.mockResolvedValue("write");
+    const { token } = await createSessionForGitHubUser(env, { login: "repo-owner", id: 201 });
+
+    const response = await app.request(
+      OWNED_REPO_PATH,
+      {
+        method: "PUT",
+        headers: { cookie: `gittensory_session=${token}`, "content-type": "application/json" },
+        body: JSON.stringify({ wantedPaths: ["src/"], settings: { agentDryRun: true, agentGlobalFreezeOverride: true } }),
+      },
+      env,
+    );
+
+    expect(response.status).toBe(200);
+    const body = await response.json() as {
+      manifest: { settings: { agentDryRun?: boolean; agentGlobalFreezeOverride?: boolean } };
+    };
+    expect(body.manifest.settings.agentDryRun).toBe(true);
+    expect(body.manifest.settings.agentGlobalFreezeOverride).toBeUndefined();
+    const effective = resolveEffectiveSettings({ agentGlobalFreezeOverride: false } as RepositorySettings, body.manifest as FocusManifest);
+    expect(effective.agentGlobalFreezeOverride).toBe(false);
+    expect(await isDbFrozenForRepo(env, effective.agentGlobalFreezeOverride)).toBe(true);
+  });
+
+  // stripMaintainerFocusManifestSettings's guard is a compound OR chain (raw not-an-object / raw array /
+  // settings null / settings not-an-object / settings array / settings missing the override key) -- each of
+  // these leaves the body untouched (no strip), same as the pre-fix behavior, but for a different structural
+  // reason each time. Covering every arm here, not just the "settings HAS the key" happy path above.
+  it.each([
+    ["a top-level non-object body", "just a string"],
+    ["a top-level array body", ["src/"]],
+    ["settings: null", { wantedPaths: ["src/"], settings: null }],
+    ["settings as a non-object", { wantedPaths: ["src/"], settings: "not-an-object" }],
+    ["settings as an array", { wantedPaths: ["src/"], settings: ["not", "a", "record"] }],
+    ["settings with no freeze-override key", { wantedPaths: ["src/"], settings: { agentDryRun: true } }],
+  ])("does not crash and passes the body through unstripped for %s", async (_label, body) => {
+    const app = createApp();
+    const env = createTestEnv({ ADMIN_GITHUB_LOGINS: "" });
+    await seedRegisteredInstalledRepo(env, 201, "repo-owner", "owned-repo");
+    mockedPermission.mockResolvedValue("write");
+    const { token } = await createSessionForGitHubUser(env, { login: "repo-owner", id: 201 });
+
+    const response = await app.request(
+      OWNED_REPO_PATH,
+      {
+        method: "PUT",
+        headers: { cookie: `gittensory_session=${token}`, "content-type": "application/json" },
+        body: JSON.stringify(body),
+      },
+      env,
+    );
+
+    expect(response.status).toBe(200);
+    await expect(response.json()).resolves.toMatchObject({ repoFullName: "repo-owner/owned-repo" });
+  });
+
   it("rejects focus-manifest writes from sessions without live GitHub write permission", async () => {
     const app = createApp();
     const env = createTestEnv({ ADMIN_GITHUB_LOGINS: "" });