Vulnerability · Published Mar 27, 2026 · Assigned by GitHub_M

CVE-2026-31950LibreChat's IDOR in SSE Stream Subscription Allows Reading Other Users' Chats

Medium 5.3

In plain English

A medium-severity improper access control in LibreChat from danny-avila. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 12% of all known vulnerabilities).

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.2%top 87.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected products (as reported)

Vendor	Product	Versions
danny-avila	LibreChat	>= 0.8.2-rc2, < 0.8.2

Weakness: CWE-284 · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N

References

https://github.com/danny-avila/LibreChat/security/advisories/GHSA-f6rf-vm44-wh5g x_refsource_CONFIRM