GHSA-w3hv-x4fp-6h6j: @grackle-ai/server has Missing WebSocket Origin Header Validation

The WebSocket upgrade handler in the server validates authentication (API key token or session cookie) but does not check the Origin header. A malicious webpage on a different origin could initiate a WebSocket connection to ws://localhost:3000/ws if it can leverage the user’s session cookie (which is SameSite=Lax, allowing top-level navigations).

This enables cross-origin WebSocket hijacking — if a user visits a malicious site while a Grackle session is active, the attacker’s page could open a WebSocket and subscribe to real-time events (session output, task updates, environment state).

Affected code:

• packages/server/src/ws-bridge.ts:80-91 — connection handler accepts WebSocket upgrades without checking req.headers.origin