LibreChat JWT and Authorization Flaws

A critical authentication bypass vulnerability exists in LibreChat version 0.8.1-rc2 where the same JWT secret is reused for both user session management and the RAG (Retrieval-Augmented Generation) API authentication. This design flaw allows authenticated users to compromise service-level authentication of the RAG API by leveraging their session tokens to access or manipulate the RAG service beyond intended privileges. No active exploitation (KEV) has been reported, but a detailed security advisory with technical analysis is publicly available from SBA Research.

LibreChat 0.8.1-rc2 improperly issues JWT tokens to authenticated users for both the LibreChat API and RAG API without adequate scope separation or validation, enabling token reuse across API boundaries. An authenticated attacker with local access can exploit this misconfiguration to access or manipulate resources in the RAG API using credentials intended only for the main LibreChat API. This authentication bypass affects all deployments of LibreChat 0.8.1-rc2, with a proof-of-concept available via the SBA Research advisory (EUVD-2026-12813), though no active KEV exploitation has been reported at this time.