CVE-2026-31950 LibreChat's IDOR in SSE Stream Subscription Allows Reading Other Users' Chats
Authenticated users can read other users' real-time chat content by guessing stream IDs due to missing ownership verification in the SSE endpoint.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-31950?
CVE-2026-31950 is a medium-severity missing authorization vulnerability in Librechat Librechat, published on 27 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim.
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.
Which versions are affected by CVE-2026-31950?
It affects 1 product.
Products include Librechat Librechat.
How do I fix CVE-2026-31950?
No fix has been published for CVE-2026-31950 yet. Limit exposure of the affected software until one is available.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-31950 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-31950 exists.
Other vulnerabilities in Librechat Librechat
- CVE-2026-32625 LibreChat Exfiltrates Server Secrets via MCP Server URL Injection
- CVE-2024-11167 Improper Access Control in danny-avila/librechat
- CVE-2026-22252 LibreChat MCP Stdio Remote Command Execution
- CVE-2025-69222 LibreChat is vulnerable to Server-Side Request Forgery due to missing restrictions
- CVE-2024-41704 Path traversal in n/a
Sources
Also known as GHSA-f6rf-vm44-wh5g.