Executive brief
@grackle-ai/server is a backend service for managing and orchestrating AI coding agents. The session cookie used to authenticate users is missing the Secure flag, which means it can be transmitted over unencrypted HTTP connections when the server is exposed to a network. An attacker on the same network could intercept the cookie and hijack user sessions.
Technical details
The vulnerability is a missing Secure flag (CWE-614) in the session cookie implementation at packages/server/src/session.ts:76. The cookie is set with HttpOnly and SameSite=Lax attributes but lacks the Secure flag, causing it to be transmitted over plain HTTP. By default, the server binds to 127.0.0.1 and uses HTTP, which is acceptable for localhost-only deployments. However, when the --allow-network flag is enabled to bind to 0.0.0.0, the server becomes network-accessible, and unencrypted cookies can be intercepted by an attacker on the network. The fix (available in version 0.70.5) conditionally adds the Secure flag when HTTPS is enabled or --allow-network is used. No authentication is required to exploit this; the attack requires network proximity to intercept the cookie.
Affected products
- Grackle @grackle-ai/server <=0.70.4
Timeline
- 2026-03-25: disclosed
- 2026-03-25: patched: Fix available in version 0.70.5