diff --git a/electron/api/route-utils.ts b/electron/api/route-utils.ts
index a0ea42b7f..f48fe0350 100644
--- a/electron/api/route-utils.ts
+++ b/electron/api/route-utils.ts
@@ -1,4 +1,16 @@
 import type { IncomingMessage, ServerResponse } from 'http';
+import { PORTS } from '../utils/config';
+
+/**
+ * Allowed CORS origins — only the Electron renderer (Vite dev or production)
+ * and the OpenClaw Gateway are permitted to make cross-origin requests.
+ */
+const ALLOWED_ORIGINS = new Set([
+  `http://127.0.0.1:${PORTS.CLAWX_DEV}`,
+  `http://localhost:${PORTS.CLAWX_DEV}`,
+  `http://127.0.0.1:${PORTS.OPENCLAW_GATEWAY}`,
+  `http://localhost:${PORTS.OPENCLAW_GATEWAY}`,
+]);
 
 export async function parseJsonBody<T>(req: IncomingMessage): Promise<T> {
   const chunks: Buffer[] = [];
@@ -12,27 +24,49 @@ export async function parseJsonBody<T>(req: IncomingMessage): Promise<T> {
   return JSON.parse(raw) as T;
 }
 
-export function setCorsHeaders(res: ServerResponse): void {
-  res.setHeader('Access-Control-Allow-Origin', '*');
+/**
+ * Validate that mutation requests (POST/PUT/DELETE) carry a JSON Content-Type.
+ * This prevents "simple request" CSRF where the browser skips the preflight
+ * when Content-Type is text/plain or application/x-www-form-urlencoded.
+ */
+export function requireJsonContentType(req: IncomingMessage): boolean {
+  if (req.method === 'GET' || req.method === 'OPTIONS' || req.method === 'HEAD') {
+    return true;
+  }
+  // Requests without a body (content-length 0 or absent) are safe — CSRF
+  // "simple request" attacks rely on sending a crafted body.
+  const contentLength = req.headers['content-length'];
+  if (contentLength === '0' || contentLength === undefined) {
+    return true;
+  }
+  const ct = req.headers['content-type'] || '';
+  return ct.includes('application/json');
+}
+
+export function setCorsHeaders(res: ServerResponse, origin?: string): void {
+  // Only reflect the Origin header back if it is in the allow-list.
+  // Omitting the header for unknown origins causes the browser to block
+  // the response — this is the intended behavior for untrusted callers.
+  if (origin && ALLOWED_ORIGINS.has(origin)) {
+    res.setHeader('Access-Control-Allow-Origin', origin);
+    res.setHeader('Vary', 'Origin');
+  }
   res.setHeader('Access-Control-Allow-Methods', 'GET,POST,PUT,DELETE,OPTIONS');
-  res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
+  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
 }
 
 export function sendJson(res: ServerResponse, statusCode: number, payload: unknown): void {
-  setCorsHeaders(res);
   res.statusCode = statusCode;
   res.setHeader('Content-Type', 'application/json; charset=utf-8');
   res.end(JSON.stringify(payload));
 }
 
 export function sendNoContent(res: ServerResponse): void {
-  setCorsHeaders(res);
   res.statusCode = 204;
   res.end();
 }
 
 export function sendText(res: ServerResponse, statusCode: number, text: string): void {
-  setCorsHeaders(res);
   res.statusCode = statusCode;
   res.setHeader('Content-Type', 'text/plain; charset=utf-8');
   res.end(text);
diff --git a/electron/api/routes/app.ts b/electron/api/routes/app.ts
index 467dc5223..c1573c007 100644
--- a/electron/api/routes/app.ts
+++ b/electron/api/routes/app.ts
@@ -1,7 +1,6 @@
 import type { IncomingMessage, ServerResponse } from 'http';
 import type { HostApiContext } from '../context';
-import { parseJsonBody } from '../route-utils';
-import { setCorsHeaders, sendJson, sendNoContent } from '../route-utils';
+import { parseJsonBody, sendJson } from '../route-utils';
 import { runOpenClawDoctor, runOpenClawDoctorFix } from '../../utils/openclaw-doctor';
 
 export async function handleAppRoutes(
@@ -11,7 +10,7 @@ export async function handleAppRoutes(
   ctx: HostApiContext,
 ): Promise<boolean> {
   if (url.pathname === '/api/events' && req.method === 'GET') {
-    setCorsHeaders(res);
+    // CORS headers are already set by the server middleware.
     res.writeHead(200, {
       'Content-Type': 'text/event-stream; charset=utf-8',
       'Cache-Control': 'no-cache, no-transform',
@@ -32,10 +31,7 @@ export async function handleAppRoutes(
     return true;
   }
 
-  if (req.method === 'OPTIONS') {
-    sendNoContent(res);
-    return true;
-  }
+  // OPTIONS is handled by the server middleware; no route-level handler needed.
 
   return false;
 }
diff --git a/electron/api/server.ts b/electron/api/server.ts
index 64523d086..73838d4d7 100644
--- a/electron/api/server.ts
+++ b/electron/api/server.ts
@@ -1,3 +1,4 @@
+import { randomBytes } from 'node:crypto';
 import { createServer, type IncomingMessage, type Server, type ServerResponse } from 'node:http';
 import { PORTS } from '../utils/config';
 import { logger } from '../utils/logger';
@@ -14,7 +15,7 @@ import { handleSkillRoutes } from './routes/skills';
 import { handleFileRoutes } from './routes/files';
 import { handleSessionRoutes } from './routes/sessions';
 import { handleCronRoutes } from './routes/cron';
-import { sendJson } from './route-utils';
+import { sendJson, setCorsHeaders, requireJsonContentType } from './route-utils';
 
 type RouteHandler = (
   req: IncomingMessage,
@@ -38,10 +39,61 @@ const routeHandlers: RouteHandler[] = [
   handleUsageRoutes,
 ];
 
+/**
+ * Per-session secret token used to authenticate Host API requests.
+ * Generated once at server start and shared with the renderer via IPC.
+ * This prevents cross-origin attackers from reading sensitive data even
+ * if they can reach 127.0.0.1:3210 (the CORS wildcard alone is not
+ * sufficient because browsers attach the Origin header but not a secret).
+ */
+let hostApiToken: string = '';
+
+/** Retrieve the current Host API auth token (for use by IPC proxy). */
+export function getHostApiToken(): string {
+  return hostApiToken;
+}
+
 export function startHostApiServer(ctx: HostApiContext, port = PORTS.CLAWX_HOST_API): Server {
+  // Generate a cryptographically random token for this session.
+  hostApiToken = randomBytes(32).toString('hex');
+
   const server = createServer(async (req, res) => {
     try {
       const requestUrl = new URL(req.url || '/', `http://127.0.0.1:${port}`);
+      // ── CORS headers ─────────────────────────────────────────
+      // Set origin-aware CORS headers early so every response
+      // (including error responses) carries them consistently.
+      const origin = req.headers.origin;
+      setCorsHeaders(res, origin);
+
+      // CORS preflight — respond before auth so browsers can negotiate.
+      if (req.method === 'OPTIONS') {
+        res.statusCode = 204;
+        res.end();
+        return;
+      }
+
+      // ── Auth gate ──────────────────────────────────────────────
+      // Every non-preflight request must carry a valid Bearer token.
+      // Accept via Authorization header (preferred) or ?token= query
+      // parameter (for EventSource which cannot set custom headers).
+      const authHeader = req.headers.authorization || '';
+      const bearerToken = authHeader.startsWith('Bearer ')
+        ? authHeader.slice(7)
+        : (requestUrl.searchParams.get('token') || '');
+      if (bearerToken !== hostApiToken) {
+        sendJson(res, 401, { success: false, error: 'Unauthorized' });
+        return;
+      }
+
+      // ── Content-Type gate (anti-CSRF) ──────────────────────────
+      // Mutation requests must use application/json to force a CORS
+      // preflight, preventing "simple request" CSRF attacks.
+      if (!requireJsonContentType(req)) {
+        sendJson(res, 415, { success: false, error: 'Content-Type must be application/json' });
+        return;
+      }
+
       for (const handler of routeHandlers) {
         if (await handler(req, res, requestUrl, ctx)) {
           return;
diff --git a/electron/main/index.ts b/electron/main/index.ts
index 1fccc07c3..d1ffb35dc 100644
--- a/electron/main/index.ts
+++ b/electron/main/index.ts
@@ -170,9 +170,19 @@ function createWindow(): BrowserWindow {
     show: false,
   });
 
-  // Handle external links
+  // Handle external links — only allow safe protocols to prevent arbitrary
+  // command execution via shell.openExternal() (e.g. file://, ms-msdt:, etc.)
   win.webContents.setWindowOpenHandler(({ url }) => {
-    shell.openExternal(url);
+    try {
+      const parsed = new URL(url);
+      if (parsed.protocol === 'https:' || parsed.protocol === 'http:') {
+        shell.openExternal(url);
+      } else {
+        logger.warn(`Blocked openExternal for disallowed protocol: ${parsed.protocol}`);
+      }
+    } catch {
+      logger.warn(`Blocked openExternal for malformed URL: ${url}`);
+    }
     return { action: 'deny' };
   });
 
diff --git a/electron/main/ipc/host-api-proxy.ts b/electron/main/ipc/host-api-proxy.ts
index 40b71ff7c..a82f56520 100644
--- a/electron/main/ipc/host-api-proxy.ts
+++ b/electron/main/ipc/host-api-proxy.ts
@@ -1,6 +1,7 @@
 import { ipcMain } from 'electron';
 import { proxyAwareFetch } from '../../utils/proxy-fetch';
 import { PORTS } from '../../utils/config';
+import { getHostApiToken } from '../../api/server';
 
 type HostApiFetchRequest = {
   path: string;
@@ -10,6 +11,10 @@ type HostApiFetchRequest = {
 };
 
 export function registerHostApiProxyHandlers(): void {
+  // Expose the per-session auth token to the renderer so the browser-fallback
+  // path in host-api.ts can authenticate against the Host API server.
+  ipcMain.handle('hostapi:token', () => getHostApiToken());
+
   ipcMain.handle('hostapi:fetch', async (_, request: HostApiFetchRequest) => {
     try {
       const path = typeof request?.path === 'string' ? request.path : '';
@@ -19,6 +24,8 @@ export function registerHostApiProxyHandlers(): void {
 
       const method = (request.method || 'GET').toUpperCase();
       const headers: Record<string, string> = { ...(request.headers || {}) };
+      // Inject the per-session auth token so the Host API server accepts this request.
+      headers['Authorization'] = `Bearer ${getHostApiToken()}`;
       let body: string | undefined;
 
       if (request.body !== undefined && request.body !== null) {
@@ -26,9 +33,11 @@ export function registerHostApiProxyHandlers(): void {
           body = request.body;
         } else {
           body = JSON.stringify(request.body);
-          if (!headers['Content-Type'] && !headers['content-type']) {
-            headers['Content-Type'] = 'application/json';
-          }
+        }
+        // Ensure Content-Type is set for requests with a body so the
+        // server's anti-CSRF Content-Type gate does not reject them.
+        if (!headers['Content-Type'] && !headers['content-type']) {
+          headers['Content-Type'] = 'application/json';
         }
       }
 
diff --git a/electron/preload/index.ts b/electron/preload/index.ts
index b3f4afbfb..69e33f685 100644
--- a/electron/preload/index.ts
+++ b/electron/preload/index.ts
@@ -23,6 +23,7 @@ const electronAPI = {
         'gateway:rpc',
         'gateway:httpProxy',
         'hostapi:fetch',
+        'hostapi:token',
         'gateway:health',
         'gateway:getControlUiUrl',
         // OpenClaw
diff --git a/src/lib/host-api.ts b/src/lib/host-api.ts
index b5a81bc48..2f3e5e689 100644
--- a/src/lib/host-api.ts
+++ b/src/lib/host-api.ts
@@ -5,6 +5,19 @@ import { normalizeAppError } from './error-model';
 const HOST_API_PORT = 3210;
 const HOST_API_BASE = `http://127.0.0.1:${HOST_API_PORT}`;
 
+/** Cached Host API auth token, fetched once from the main process via IPC. */
+let cachedHostApiToken: string | null = null;
+
+async function getHostApiToken(): Promise<string> {
+  if (cachedHostApiToken) return cachedHostApiToken;
+  try {
+    cachedHostApiToken = await invokeIpc<string>('hostapi:token');
+  } catch {
+    cachedHostApiToken = '';
+  }
+  return cachedHostApiToken ?? '';
+}
+
 type HostApiProxyResponse = {
   ok?: boolean;
   data?: {
@@ -182,10 +195,12 @@ export async function hostApiFetch<T>(path: string, init?: RequestInit): Promise
   }
 
   // Browser-only fallback (non-Electron environments).
+  const token = await getHostApiToken();
   const response = await fetch(`${HOST_API_BASE}${path}`, {
     ...init,
     headers: {
       'Content-Type': 'application/json',
+      'Authorization': `Bearer ${token}`,
       ...(init?.headers || {}),
     },
   });
@@ -204,7 +219,11 @@ export async function hostApiFetch<T>(path: string, init?: RequestInit): Promise
 }
 
 export function createHostEventSource(path = '/api/events'): EventSource {
-  return new EventSource(`${HOST_API_BASE}${path}`);
+  // EventSource does not support custom headers, so pass the auth token
+  // as a query parameter. The server accepts both mechanisms.
+  const separator = path.includes('?') ? '&' : '?';
+  const tokenParam = `token=${encodeURIComponent(cachedHostApiToken ?? '')}`;
+  return new EventSource(`${HOST_API_BASE}${path}${separator}${tokenParam}`);
 }
 
 export function getHostApiBase(): string {