Loading vulnerability details…
CVSS v3.1
6.8
EPSS
0.24%
Published
Mar 27, 2026
Modified
Mar 30, 2026
Public PoC / Exploit (1)
All weaponized →Links to public security research (Exploit-DB, Nuclei, Trickest, GitHub) for defensive use only.
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.
CVSS Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:NWeaknesses (CWE)
References (1)