Openclaw cli: OpenClaw's Browser Relay /cdp websocket is missing auth which could allow cross-tab cookie access (CVE-2026-28458)

The Browser Relay service in affected OpenClaw CLI versions exposes a local WebSocket endpoint at ws://127.0.0.1:18792/cdp for forwarding Chrome DevTools Protocol messages. The endpoint verified the TCP peer was loopback but did not require authentication or block cross-origin requests initiated by the browser. This allowed a malicious website to connect to the relay and use CDP to access session cookies from other tabs and execute JavaScript in their context. The fix introduced a required shared secret HTTP header (x-openclaw-relay-token) and rejects connections with invalid Origin headers or when the extension is not connected.

An attacker controlling a website visited by a user with the vulnerable Browser Relay extension active could access sensitive information such as session cookies from other open tabs and execute JavaScript in the context of those tabs. This compromises user privacy and security by enabling cross-tab cookie theft and script execution. The attack requires the user to have the Browser Relay extension installed and active and to visit a malicious or untrusted site.

A fix is available in openclaw version 2026.2.1 and later, which enforces authentication via a shared secret header and restricts WebSocket connections by Origin. Users should update to openclaw@>=2026.2.1 to remediate this vulnerability. If immediate updating is not possible, users should disable the Browser Relay extension or relay server and avoid visiting untrusted websites until patched.