diff --git a/src/web-server/index.ts b/src/web-server/index.ts
index 6ec39e00..6015c004 100644
--- a/src/web-server/index.ts
+++ b/src/web-server/index.ts
@@ -79,6 +79,10 @@ export async function startServer(options: ServerOptions): Promise<ServerInstanc
   const { usageRoutes } = await import('./usage-routes');
   app.use('/api/usage', usageRoutes);
 
+  // CLIProxy local reverse proxy (avoids cross-origin issues in Docker)
+  const cliproxyLocalProxy = (await import('./routes/cliproxy-local-proxy')).default;
+  app.use('/cliproxy-local', cliproxyLocalProxy);
+
   // Dev mode: use Vite middleware for HMR
   if (options.dev) {
     const { createServer: createViteServer } = await import('vite');
diff --git a/src/web-server/routes/cliproxy-local-proxy.ts b/src/web-server/routes/cliproxy-local-proxy.ts
new file mode 100644
index 00000000..1268fc5b
--- /dev/null
+++ b/src/web-server/routes/cliproxy-local-proxy.ts
@@ -0,0 +1,49 @@
+/**
+ * CLIProxy Local Reverse Proxy
+ *
+ * Proxies requests from the dashboard to the local CLIProxy service
+ * running on 127.0.0.1:8317 inside the same host/container.
+ *
+ * This eliminates cross-origin issues when the dashboard and CLIProxy
+ * run on different ports (e.g., inside Docker containers where the
+ * browser cannot reach the internal CLIProxy port directly).
+ *
+ * Mounted at: /cliproxy-local/*  →  http://127.0.0.1:{port}/*
+ */
+
+import { Router, Request, Response } from 'express';
+import http from 'http';
+import { CLIPROXY_DEFAULT_PORT } from '../../cliproxy/config/port-manager';
+
+const router = Router();
+
+router.all('/*', (req: Request, res: Response) => {
+  // Strip the mount prefix — req.url already has it removed by Express
+  const targetPath = req.url || '/';
+
+  const options: http.RequestOptions = {
+    hostname: '127.0.0.1',
+    port: CLIPROXY_DEFAULT_PORT,
+    path: targetPath,
+    method: req.method,
+    headers: {
+      ...req.headers,
+      host: `127.0.0.1:${CLIPROXY_DEFAULT_PORT}`,
+    },
+  };
+
+  const proxyReq = http.request(options, (proxyRes) => {
+    res.writeHead(proxyRes.statusCode ?? 502, proxyRes.headers);
+    proxyRes.pipe(res, { end: true });
+  });
+
+  proxyReq.on('error', () => {
+    if (!res.headersSent) {
+      res.status(502).json({ error: 'CLIProxy is not reachable' });
+    }
+  });
+
+  req.pipe(proxyReq, { end: true });
+});
+
+export default router;
diff --git a/ui/src/components/cliproxy/control-panel-embed.tsx b/ui/src/components/cliproxy/control-panel-embed.tsx
index d256c1f0..8755ab44 100644
--- a/ui/src/components/cliproxy/control-panel-embed.tsx
+++ b/ui/src/components/cliproxy/control-panel-embed.tsx
@@ -78,11 +78,12 @@ export function ControlPanelEmbed({ port = CLIPROXY_DEFAULT_PORT }: ControlPanel
       };
     }
 
-    // Local mode - use effective management secret from auth tokens API
+    // Local mode - proxy through dashboard server to avoid cross-origin/port issues
+    // (e.g., in Docker the browser cannot reach the internal CLIProxy port directly)
     const effectiveSecret = authTokens?.managementSecret?.value || 'ccs';
     return {
-      managementUrl: `http://localhost:${port}/management.html`,
-      checkUrl: `http://localhost:${port}/`,
+      managementUrl: '/cliproxy-local/management.html',
+      checkUrl: '/cliproxy-local/',
       authToken: effectiveSecret,
       isRemote: false,
       displayHost: `localhost:${port}`,
@@ -98,19 +99,36 @@ export function ControlPanelEmbed({ port = CLIPROXY_DEFAULT_PORT }: ControlPanel
 
     const checkConnection = async () => {
       try {
-        const response = await fetch(checkUrl, {
-          signal: controller.signal,
-        });
-        if (response.ok) {
-          setIsConnected(true);
-          setError(null);
+        if (isRemote) {
+          // Remote mode: use the test endpoint via same-origin API to avoid CORS
+          const remote = cliproxyConfig?.remote;
+          const result = await api.cliproxyServer.test({
+            host: remote?.host ?? '',
+            port: remote?.port,
+            protocol: remote?.protocol ?? 'http',
+            authToken: remote?.auth_token,
+          });
+          if (result?.reachable) {
+            setIsConnected(true);
+            setError(null);
+          } else {
+            setIsConnected(false);
+            setError(
+              result?.error
+                ? `Remote CLIProxy at ${displayHost}: ${result.error}`
+                : `Remote CLIProxy at ${displayHost} returned an error`
+            );
+          }
         } else {
-          setIsConnected(false);
-          setError(
-            isRemote
-              ? `Remote CLIProxy at ${displayHost} returned an error`
-              : 'CLIProxy returned an error'
-          );
+          // Local mode: use same-origin API to check proxy status (avoids CORS)
+          const status = await api.cliproxy.proxyStatus();
+          if (status.running) {
+            setIsConnected(true);
+            setError(null);
+          } else {
+            setIsConnected(false);
+            setError('CLIProxy is not running');
+          }
         }
       } catch (e) {
         // Ignore abort errors (component unmounting)
@@ -131,7 +149,7 @@ export function ControlPanelEmbed({ port = CLIPROXY_DEFAULT_PORT }: ControlPanel
 
     // Cleanup: abort fetch on unmount
     return () => controller.abort();
-  }, [checkUrl, isRemote, displayHost]);
+  }, [isRemote, displayHost, cliproxyConfig]);
 
   const postAutoLoginCredentials = useCallback(() => {
     // Auto-login can only run when iframe has loaded and authToken is available.
@@ -140,12 +158,21 @@ export function ControlPanelEmbed({ port = CLIPROXY_DEFAULT_PORT }: ControlPanel
     }
 
     try {
-      // Derive apiBase from checkUrl (remove trailing slash)
-      const apiBase = checkUrl.replace(/\/$/, '');
+      // Derive apiBase and targetOrigin from checkUrl
+      // Local mode: checkUrl is a relative path (/cliproxy-local/) → same origin
+      // Remote mode: checkUrl is an absolute URL (http://host:port/)
+      const isRelative = checkUrl.startsWith('/');
+      const apiBase = isRelative
+        ? `${window.location.origin}/cliproxy-local`
+        : checkUrl.replace(/\/$/, '');
+      const targetOrigin = isRelative ? window.location.origin : apiBase;
 
       // Security: Validate iframe src matches target origin before sending credentials
       const iframeSrc = iframeRef.current.src;
-      if (!iframeSrc.startsWith(apiBase)) {
+      const resolvedSrc = isRelative
+        ? new URL(iframeSrc, window.location.origin).href
+        : iframeSrc;
+      if (!resolvedSrc.startsWith(targetOrigin)) {
         console.warn('[ControlPanelEmbed] Iframe origin mismatch, skipping postMessage');
         return;
       }
@@ -157,7 +184,7 @@ export function ControlPanelEmbed({ port = CLIPROXY_DEFAULT_PORT }: ControlPanel
           apiBase,
           managementKey: authToken,
         },
-        apiBase
+        targetOrigin
       );
     } catch (e) {
       // Cross-origin restriction - expected if not same origin