LibreChat — Xss (CVE-2025-66452)
Date: 2025-12
Affected: librechat/librechat
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2025-66452
CWE: CWE-79
CVSS: 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)

LibreChat is a ChatGPT clone with additional features. In versions 0.8.0 and below, there is no handler for JSON parsing errors; SyntaxError from express.json() includes user input in the error message, which gets reflected in responses. User input (including HTML/JavaScript) can be exposed in error responses, creating an XSS risk if Content-Type isn't strictly enforced. This issue does not have a fix at the time of publication.


Mitigations:

Architectural layers (MAESTRO):