CVE-2026-56104: Chainlit contains a session hijacking vulnerability
(updated )
Chainlit before 2.10.1 contains a session hijacking vulnerability that allows unauthenticated attackers to restore and inherit authenticated user sessions by presenting a valid sessionId during WebSocket session restoration without ownership verification. Attackers can exploit the restore_existing_session path to assume a victim’s permissions and roles, enabling unauthorized invocation of tools and access to data restricted to the authenticated victim.
References
- github.com/Chainlit/chainlit/commit/5effb664f1e0af4a4f0a42fe63ea979676039a7f
- github.com/Chainlit/chainlit/pull/2857
- github.com/Chainlit/chainlit/releases/tag/2.10.1
- github.com/advisories/GHSA-c39v-8hrw-h448
- nvd.nist.gov/vuln/detail/CVE-2026-56104
- www.vulncheck.com/advisories/chainlit-session-hijacking-via-websocket-session-restoration
Code Behaviors & Features
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