CVE-2026-31950

LibreChat's IDOR in SSE Stream Subscription Allows Reading Other Users' Chats

State: Published
Severity: 5.3 Medium
Published: Mar 27, 2026
Updated: Mar 27, 2026
Reserved: Mar 10, 2026

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.

Scores

CVSS	Score	Vector	Source
3.1	5.3 Medium	CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N	GitHub_M

Weaknesses

CWE-284 Improper Access Control

Affected Products

Product	Versions
LibreChatdanny-avila	>= 0.8.2-rc2, < 0.8.2Affected

References

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

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