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OpenAdvisories
High · 8.2 CVE-2026-56104 EUVD-2026-38285GHSA-c39v-8hrw-h448PYSEC-2026-4028

Chainlit < 2.10.1 Session Hijacking via WebSocket Session Restoration

Published Jun 22, 2026 · Updated Nov 8, 2026 · Assigned by VulnCheck

Description

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.

Affected products

VendorProductAffectedFixed
Chainlit chainlit < 2.10.1 2.10.1

Affected packages

EcosystemPackageAffectedFixedRecord
PyPI chainlit < 2.10.1 2.10.1 GHSA-c39v-8hrw-h448

References