LibreChat — Data Exfiltration (CVE-2026-44653)
Date: 2026-06
Affected: librechat/librechat
Attack vector: data-exfiltration
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2026-44653
CWE: CWE-201
CVSS: 6.5 (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N)

LibreChat is an enhanced ChatGPT clone that supports multiple AI providers. In versions up to and including 0.8.3, users with only `VIEW` access to an MCP server can retrieve the server's decrypted admin-managed secrets through `GET /api/mcp/servers` and `GET /api/mcp/servers/:serverName`. The returned config includes plaintext values for `apiKey.key` and `oauth.client_secret`. This allows viewers of a shared MCP server to exfiltrate the underlying provider credentials. Version 0.8..4 contains a patch. Other remediations include: never returning decrypted admin-managed secrets to non-owners; redacting apiKey.key and oauth.client_secret from all API responses consider returning only boolean presence indicators for secrets, similar to the auth-values route pattern; and, if owners need to edit configs without re-entering secrets, preserving secrets server-side and returning placeholders instead of plaintext.


Mitigations:

Architectural layers (MAESTRO):