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.

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.

EPSS: 0.002 (11.2th percentile) — read the EPSS interpretation.

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.

Affected products

Danny-avila Librechat — versions >= 0.8.2-rc2, < 0.8.2
Librechat — versions 0.8.2

Weakness classification (CWE)

References

security-advisories@github.com (x_refsource_CONFIRM, 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.