LibreChat — Vulnerability (CVE-2026-31950)
Date: 2026-03
Affected: librechat/librechat
Attack vector: auth-bypass
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-31950
CWE: CWE-284
CWE-639
CVSS: 5.3 (CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N)

LibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc2 through 0.8.2-rc3, the SSE streaming endpoint `/api/agents/chat/stream/:streamId` does not verify that the requesting user owns the stream. Any authenticated user who obtains or guesses a valid stream ID can subscribe and read another user's real-time chat content, including messages, AI responses, and tool invocations. Version 0.8.2 patches the issue.


Mitigations:

Architectural layers (MAESTRO):