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 6.8EPSS 0.244%Risk 0.69
View source- Published
- 2026-03-27 20:16:30
- Affected versions
- >=0.8.2-rc1,<0.8.3-rc2
- Type
- Core software
- Vector
- CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N