diff --git a/extensions/nextcloud-talk/src/monitor.replay.test.ts b/extensions/nextcloud-talk/src/monitor.replay.test.ts
index 68cf8af308f..125a306a359 100644
--- a/extensions/nextcloud-talk/src/monitor.replay.test.ts
+++ b/extensions/nextcloud-talk/src/monitor.replay.test.ts
@@ -1,5 +1,6 @@
 import { describe, expect, it, vi } from "vitest";
 import { createMockIncomingRequest } from "../../../test/helpers/mock-incoming-request.js";
+import { WEBHOOK_RATE_LIMIT_DEFAULTS } from "../runtime-api.js";
 import { readNextcloudTalkWebhookBody } from "./monitor.js";
 import { createSignedCreateMessageRequest } from "./monitor.test-fixtures.js";
 import { startWebhookServer } from "./monitor.test-harness.js";
@@ -145,3 +146,57 @@ describe("createNextcloudTalkWebhookServer payload validation", () => {
     expect(await response.json()).toEqual({ error: "Invalid payload format" });
   });
 });
+
+describe("createNextcloudTalkWebhookServer auth rate limiting", () => {
+  it("rate limits repeated invalid signature attempts from the same source", async () => {
+    const harness = await startWebhookServer({
+      path: "/nextcloud-auth-rate-limit",
+      onMessage: vi.fn(),
+    });
+    const { body, headers } = createSignedCreateMessageRequest();
+    const invalidHeaders = {
+      ...headers,
+      "x-nextcloud-talk-signature": "invalid-signature",
+    };
+
+    let firstResponse: Response | undefined;
+    let lastResponse: Response | undefined;
+    for (let attempt = 0; attempt <= WEBHOOK_RATE_LIMIT_DEFAULTS.maxRequests; attempt += 1) {
+      const response = await fetch(harness.webhookUrl, {
+        method: "POST",
+        headers: invalidHeaders,
+        body,
+      });
+      if (attempt === 0) {
+        firstResponse = response;
+      }
+      lastResponse = response;
+    }
+
+    expect(firstResponse).toBeDefined();
+    expect(firstResponse?.status).toBe(401);
+    expect(lastResponse).toBeDefined();
+    expect(lastResponse?.status).toBe(429);
+    expect(await lastResponse?.text()).toBe("Too Many Requests");
+  });
+
+  it("does not rate limit valid signed webhook bursts from the same source", async () => {
+    const harness = await startWebhookServer({
+      path: "/nextcloud-auth-rate-limit-valid",
+      onMessage: vi.fn(),
+    });
+    const { body, headers } = createSignedCreateMessageRequest();
+
+    let lastResponse: Response | undefined;
+    for (let attempt = 0; attempt <= WEBHOOK_RATE_LIMIT_DEFAULTS.maxRequests; attempt += 1) {
+      lastResponse = await fetch(harness.webhookUrl, {
+        method: "POST",
+        headers,
+        body,
+      });
+    }
+
+    expect(lastResponse).toBeDefined();
+    expect(lastResponse?.status).toBe(200);
+  });
+});
diff --git a/extensions/nextcloud-talk/src/monitor.ts b/extensions/nextcloud-talk/src/monitor.ts
index 025eb2173bd..ecf3b039193 100644
--- a/extensions/nextcloud-talk/src/monitor.ts
+++ b/extensions/nextcloud-talk/src/monitor.ts
@@ -6,6 +6,8 @@ import {
 } from "openclaw/plugin-sdk/extension-shared";
 import { z } from "zod";
 import {
+  WEBHOOK_RATE_LIMIT_DEFAULTS,
+  createAuthRateLimiter,
   type RuntimeEnv,
   isRequestBodyLimitError,
   readRequestBodyWithLimit,
@@ -32,6 +34,7 @@ const DEFAULT_WEBHOOK_BODY_TIMEOUT_MS = 30_000;
 const PREAUTH_WEBHOOK_MAX_BODY_BYTES = 64 * 1024;
 const PREAUTH_WEBHOOK_BODY_TIMEOUT_MS = 5_000;
 const HEALTH_PATH = "/healthz";
+const WEBHOOK_AUTH_RATE_LIMIT_SCOPE = "nextcloud-talk-webhook-auth";
 const NextcloudTalkWebhookPayloadSchema: z.ZodType<NextcloudTalkWebhookPayload> = z.object({
   type: z.enum(["Create", "Update", "Delete"]),
   actor: z.object({
@@ -125,6 +128,8 @@ function verifyWebhookSignature(params: {
   body: string;
   secret: string;
   res: ServerResponse;
+  clientIp: string;
+  authRateLimiter: ReturnType<typeof createAuthRateLimiter>;
 }): boolean {
   const isValid = verifyNextcloudTalkSignature({
     signature: params.headers.signature,
@@ -133,9 +138,11 @@ function verifyWebhookSignature(params: {
     secret: params.secret,
   });
   if (!isValid) {
+    params.authRateLimiter.recordFailure(params.clientIp, WEBHOOK_AUTH_RATE_LIMIT_SCOPE);
     writeWebhookError(params.res, 401, WEBHOOK_ERRORS.invalidSignature);
     return false;
   }
+  params.authRateLimiter.reset(params.clientIp, WEBHOOK_AUTH_RATE_LIMIT_SCOPE);
   return true;
 }
 
@@ -203,6 +210,13 @@ export function createNextcloudTalkWebhookServer(opts: NextcloudTalkWebhookServe
   const readBody = opts.readBody ?? readNextcloudTalkWebhookBody;
   const isBackendAllowed = opts.isBackendAllowed;
   const shouldProcessMessage = opts.shouldProcessMessage;
+  const webhookAuthRateLimiter = createAuthRateLimiter({
+    maxAttempts: WEBHOOK_RATE_LIMIT_DEFAULTS.maxRequests,
+    windowMs: WEBHOOK_RATE_LIMIT_DEFAULTS.windowMs,
+    lockoutMs: WEBHOOK_RATE_LIMIT_DEFAULTS.windowMs,
+    exemptLoopback: false,
+    pruneIntervalMs: WEBHOOK_RATE_LIMIT_DEFAULTS.windowMs,
+  });
 
   const server = createServer(async (req: IncomingMessage, res: ServerResponse) => {
     if (req.url === HEALTH_PATH) {
@@ -217,6 +231,13 @@ export function createNextcloudTalkWebhookServer(opts: NextcloudTalkWebhookServe
       return;
     }
 
+    const clientIp = req.socket.remoteAddress ?? "unknown";
+    if (!webhookAuthRateLimiter.check(clientIp, WEBHOOK_AUTH_RATE_LIMIT_SCOPE).allowed) {
+      res.writeHead(429);
+      res.end("Too Many Requests");
+      return;
+    }
+
     try {
       const headers = validateWebhookHeaders({
         req,
@@ -234,6 +255,8 @@ export function createNextcloudTalkWebhookServer(opts: NextcloudTalkWebhookServe
         body,
         secret,
         res,
+        clientIp,
+        authRateLimiter: webhookAuthRateLimiter,
       });
       if (!hasValidSignature) {
         return;
diff --git a/src/plugin-sdk/nextcloud-talk.ts b/src/plugin-sdk/nextcloud-talk.ts
index 934ead7568b..b189411aa7d 100644
--- a/src/plugin-sdk/nextcloud-talk.ts
+++ b/src/plugin-sdk/nextcloud-talk.ts
@@ -2,6 +2,7 @@
 // Keep this list additive and scoped to symbols used under extensions/nextcloud-talk.
 
 export { logInboundDrop } from "../channels/logging.js";
+export { createAuthRateLimiter } from "../gateway/auth-rate-limit.js";
 export { resolveMentionGatingWithBypass } from "../channels/mention-gating.js";
 export type { AllowlistMatch } from "../channels/plugins/allowlist-match.js";
 export {
@@ -70,10 +71,11 @@ export {
   requireOpenAllowFrom,
 } from "../config/zod-schema.core.js";
 export {
+  WEBHOOK_RATE_LIMIT_DEFAULTS,
   isRequestBodyLimitError,
   readRequestBodyWithLimit,
   requestBodyErrorToText,
-} from "../infra/http-body.js";
+} from "./webhook-ingress.js";
 export { waitForAbortSignal } from "../infra/abort-signal.js";
 export { fetchWithSsrFGuard } from "../infra/net/fetch-guard.js";
 export { emptyPluginConfigSchema } from "../plugins/config-schema.js";