diff --git a/CHANGELOG.md b/CHANGELOG.md
index c3e628cf5e..72f95f72f6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -69,6 +69,7 @@ Docs: https://docs.openclaw.ai
 - Security/Link understanding: block loopback/internal host patterns and private/mapped IPv6 addresses in extracted URL handling to close SSRF bypasses in link CLI flows. (#15604) Thanks @AI-Reviewer-QS.
 - Security/Browser: constrain `POST /trace/stop`, `POST /wait/download`, and `POST /download` output paths to OpenClaw temp roots and reject traversal/escape paths.
 - Security/Browser: require auth for the sandbox browser bridge server (protects `/profiles`, `/tabs`, CDP URLs, and other control endpoints). Thanks @jackhax.
+- Security: bind local helper servers to loopback and fail closed on non-loopback OAuth callback hosts (reduces localhost/LAN attack surface).
 - Security/Canvas: serve A2UI assets via the shared safe-open path (`openFileWithinRoot`) to close traversal/TOCTOU gaps, with traversal and symlink regression coverage. (#10525) Thanks @abdelsfane.
 - Security/WhatsApp: enforce `0o600` on `creds.json` and `creds.json.bak` on save/backup/restore paths to reduce credential file exposure. (#10529) Thanks @abdelsfane.
 - Security/Gateway: sanitize and truncate untrusted WebSocket header values in pre-handshake close logs to reduce log-poisoning risk. Thanks @thewilloftheshadow.
diff --git a/src/agents/sandbox/browser.ts b/src/agents/sandbox/browser.ts
index b1aa01451f..6e3c9348d8 100644
--- a/src/agents/sandbox/browser.ts
+++ b/src/agents/sandbox/browser.ts
@@ -1,3 +1,4 @@
+import crypto from "node:crypto";
 import type { SandboxBrowserContext, SandboxConfig } from "./types.js";
 import { startBrowserBridgeServer, stopBrowserBridgeServer } from "../../browser/bridge-server.js";
 import { type ResolvedBrowserConfig, resolveProfile } from "../../browser/config.js";
@@ -149,13 +150,24 @@ export async function ensureSandboxBrowser(params: {
       ? await readDockerPort(containerName, params.cfg.browser.noVncPort)
       : null;
 
-  const desiredAuthToken = params.bridgeAuth?.token?.trim() || undefined;
-  const desiredAuthPassword = params.bridgeAuth?.password?.trim() || undefined;
-
   const existing = BROWSER_BRIDGES.get(params.scopeKey);
   const existingProfile = existing
     ? resolveProfile(existing.bridge.state.resolved, DEFAULT_OPENCLAW_BROWSER_PROFILE_NAME)
     : null;
+
+  let desiredAuthToken = params.bridgeAuth?.token?.trim() || undefined;
+  let desiredAuthPassword = params.bridgeAuth?.password?.trim() || undefined;
+  if (!desiredAuthToken && !desiredAuthPassword) {
+    // Always require auth for the sandbox bridge server, even if gateway auth
+    // mode doesn't produce a shared secret (e.g. trusted-proxy).
+    // Keep it stable across calls by reusing the existing bridge auth.
+    desiredAuthToken = existing?.authToken;
+    desiredAuthPassword = existing?.authPassword;
+    if (!desiredAuthToken && !desiredAuthPassword) {
+      desiredAuthToken = crypto.randomBytes(24).toString("hex");
+    }
+  }
+
   const shouldReuse =
     existing && existing.containerName === containerName && existingProfile?.cdpPort === mappedCdp;
   const authMatches =
diff --git a/src/browser/bridge-auth-registry.ts b/src/browser/bridge-auth-registry.ts
new file mode 100644
index 0000000000..ef9346bf34
--- /dev/null
+++ b/src/browser/bridge-auth-registry.ts
@@ -0,0 +1,34 @@
+type BridgeAuth = {
+  token?: string;
+  password?: string;
+};
+
+// In-process registry for loopback-only bridge servers that require auth, but
+// are addressed via dynamic ephemeral ports (e.g. sandbox browser bridge).
+const authByPort = new Map<number, BridgeAuth>();
+
+export function setBridgeAuthForPort(port: number, auth: BridgeAuth): void {
+  if (!Number.isFinite(port) || port <= 0) {
+    return;
+  }
+  const token = typeof auth.token === "string" ? auth.token.trim() : "";
+  const password = typeof auth.password === "string" ? auth.password.trim() : "";
+  authByPort.set(port, {
+    token: token || undefined,
+    password: password || undefined,
+  });
+}
+
+export function getBridgeAuthForPort(port: number): BridgeAuth | undefined {
+  if (!Number.isFinite(port) || port <= 0) {
+    return undefined;
+  }
+  return authByPort.get(port);
+}
+
+export function deleteBridgeAuthForPort(port: number): void {
+  if (!Number.isFinite(port) || port <= 0) {
+    return;
+  }
+  authByPort.delete(port);
+}
diff --git a/src/browser/bridge-server.auth.test.ts b/src/browser/bridge-server.auth.test.ts
index de0ef63668..e5b3904b10 100644
--- a/src/browser/bridge-server.auth.test.ts
+++ b/src/browser/bridge-server.auth.test.ts
@@ -73,4 +73,12 @@ describe("startBrowserBridgeServer auth", () => {
     });
     expect(authed.status).toBe(200);
   });
+
+  it("requires auth params", async () => {
+    await expect(
+      startBrowserBridgeServer({
+        resolved: buildResolvedConfig(),
+      }),
+    ).rejects.toThrow(/requires auth/i);
+  });
 });
diff --git a/src/browser/bridge-server.ts b/src/browser/bridge-server.ts
index cb69d510fe..4ee73167ae 100644
--- a/src/browser/bridge-server.ts
+++ b/src/browser/bridge-server.ts
@@ -4,7 +4,9 @@ import type { AddressInfo } from "node:net";
 import express from "express";
 import type { ResolvedBrowserConfig } from "./config.js";
 import type { BrowserRouteRegistrar } from "./routes/types.js";
+import { isLoopbackHost } from "../gateway/net.js";
 import { safeEqualSecret } from "../security/secret-equal.js";
+import { deleteBridgeAuthForPort, setBridgeAuthForPort } from "./bridge-auth-registry.js";
 import { registerBrowserRoutes } from "./routes/index.js";
 import {
   type BrowserServerState,
@@ -89,6 +91,9 @@ export async function startBrowserBridgeServer(params: {
   onEnsureAttachTarget?: (profile: ProfileContext["profile"]) => Promise<void>;
 }): Promise<BrowserBridge> {
   const host = params.host ?? "127.0.0.1";
+  if (!isLoopbackHost(host)) {
+    throw new Error(`bridge server must bind to loopback host (got ${host})`);
+  }
   const port = params.port ?? 0;
 
   const app = express();
@@ -109,6 +114,9 @@ export async function startBrowserBridgeServer(params: {
 
   const authToken = params.authToken?.trim() || undefined;
   const authPassword = params.authPassword?.trim() || undefined;
+  if (!authToken && !authPassword) {
+    throw new Error("bridge server requires auth (authToken/authPassword missing)");
+  }
   if (authToken || authPassword) {
     app.use((req, res, next) => {
       if (isAuthorizedBrowserRequest(req, { token: authToken, password: authPassword })) {
@@ -142,11 +150,21 @@ export async function startBrowserBridgeServer(params: {
   state.port = resolvedPort;
   state.resolved.controlPort = resolvedPort;
 
+  setBridgeAuthForPort(resolvedPort, { token: authToken, password: authPassword });
+
   const baseUrl = `http://${host}:${resolvedPort}`;
   return { server, port: resolvedPort, baseUrl, state };
 }
 
 export async function stopBrowserBridgeServer(server: Server): Promise<void> {
+  try {
+    const address = server.address() as AddressInfo | null;
+    if (address?.port) {
+      deleteBridgeAuthForPort(address.port);
+    }
+  } catch {
+    // ignore
+  }
   await new Promise<void>((resolve) => {
     server.close(() => resolve());
   });
diff --git a/src/browser/client-fetch.ts b/src/browser/client-fetch.ts
index 3c671b27ed..bcc8f9fadd 100644
--- a/src/browser/client-fetch.ts
+++ b/src/browser/client-fetch.ts
@@ -1,5 +1,6 @@
 import { formatCliCommand } from "../cli/command-format.js";
 import { loadConfig } from "../config/config.js";
+import { getBridgeAuthForPort } from "./bridge-auth-registry.js";
 import { resolveBrowserControlAuth } from "./control-auth.js";
 import {
   createBrowserControlContext,
@@ -37,13 +38,36 @@ function withLoopbackBrowserAuth(
     const auth = resolveBrowserControlAuth(cfg);
     if (auth.token) {
       headers.set("Authorization", `Bearer ${auth.token}`);
-    } else if (auth.password) {
+      return { ...init, headers };
+    }
+    if (auth.password) {
       headers.set("x-openclaw-password", auth.password);
+      return { ...init, headers };
     }
   } catch {
     // ignore config/auth lookup failures and continue without auth headers
   }
 
+  // Sandbox bridge servers can run with per-process ephemeral auth on dynamic ports.
+  // Fall back to the in-memory registry if config auth is not available.
+  try {
+    const parsed = new URL(url);
+    const port =
+      parsed.port && Number.parseInt(parsed.port, 10) > 0
+        ? Number.parseInt(parsed.port, 10)
+        : parsed.protocol === "https:"
+          ? 443
+          : 80;
+    const bridgeAuth = getBridgeAuthForPort(port);
+    if (bridgeAuth?.token) {
+      headers.set("Authorization", `Bearer ${bridgeAuth.token}`);
+    } else if (bridgeAuth?.password) {
+      headers.set("x-openclaw-password", bridgeAuth.password);
+    }
+  } catch {
+    // ignore
+  }
+
   return { ...init, headers };
 }
 
diff --git a/src/commands/chutes-oauth.ts b/src/commands/chutes-oauth.ts
index 91f56fd51b..1925649bb4 100644
--- a/src/commands/chutes-oauth.ts
+++ b/src/commands/chutes-oauth.ts
@@ -8,6 +8,7 @@ import {
   generateChutesPkce,
   parseOAuthCallbackInput,
 } from "../agents/chutes-oauth.js";
+import { isLoopbackHost } from "../gateway/net.js";
 
 type OAuthPrompt = {
   message: string;
@@ -44,6 +45,11 @@ async function waitForLocalCallback(params: {
     throw new Error(`Chutes OAuth redirect URI must be http:// (got ${params.redirectUri})`);
   }
   const hostname = redirectUrl.hostname || "127.0.0.1";
+  if (!isLoopbackHost(hostname)) {
+    throw new Error(
+      `Chutes OAuth redirect hostname must be loopback (got ${hostname}). Use http://127.0.0.1:<port>/...`,
+    );
+  }
   const port = redirectUrl.port ? Number.parseInt(redirectUrl.port, 10) : 80;
   const expectedPath = redirectUrl.pathname || "/";
 
diff --git a/src/media/server.ts b/src/media/server.ts
index 6f7543b1b2..62dd5ef2d7 100644
--- a/src/media/server.ts
+++ b/src/media/server.ts
@@ -96,7 +96,7 @@ export async function startMediaServer(
   const app = express();
   attachMediaRoutes(app, ttlMs, runtime);
   return await new Promise((resolve, reject) => {
-    const server = app.listen(port);
+    const server = app.listen(port, "127.0.0.1");
     server.once("listening", () => resolve(server));
     server.once("error", (err) => {
       runtime.error(danger(`Media server failed: ${String(err)}`));