cvedb.io
CVE-2026-31951
MEDIUM · CVSS 6.8
EPSS exploitation probability: 0%
Published 2026-03-27T20:16:30.397 · Last modified 2026-06-17T10:34:49.693

Summary

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.

Affected products

librechat — librechat

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.