Auth bypass in Danny-Avila Librechat
CVE-2026-31950
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (18.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 18.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
- Danny-Avila Librechat — versions >= 0.8.2-rc2, < 0.8.2
- Librechat — versions 0.8.2
Weakness classification (CWE)
References
- github.com/danny-avila/LibreChat/security/advisories/GHSA-f6rf-vm44-wh5g (Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-31950?
- CVE-2026-31950 is a medium-severity vulnerability in Danny-Avila Librechat, classified under Improper Access Control. CVSS score: 5.3/10. Published 2026-03-27.
- How severe is CVE-2026-31950?
- Medium severity. CVSS v3 base score is 5.3 out of 10.