Description

LibreChat is a ChatGPT clone with additional features. In versions 0.8.2-rc1 through 0.8.3-rc1, user-created MCP (Model Context Protocol) servers can include arbitrary HTTP headers that undergo credential placeholder substitution. An attacker can create a malicious MCP server with headers containing `{{LIBRECHAT_OPENID_ACCESS_TOKEN}}` (and others), causing victims who call tools on that server to have their OAuth tokens exfiltrated. Version 0.8.3-rc2 fixes the issue.

INFO

Published Date :

2026-03-27T19:29:25.892Z

Last Modified :

2026-03-27T19:29:25.892Z

Source :

GitHub_M
AFFECTED PRODUCTS

The following products are affected by CVE-2026-31951 vulnerability.

No data.

REFERENCES

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-31951.

CVSS Vulnerability Scoring System

Detailed values of each vector for above chart.
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact