CVE-2025-66452 MEDIUM

CVE-2025-66452: LibreChat's lack of JSON parsing error handling can lead to XSS

Vendor Danny-Avila
Product LibreChat
Weakness CWE-79 · XSS
Published December 11, 2025
Last update December 12, 2025

CVSS base score

5.3/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

December 11, 2025 CVE published
December 12, 2025 Record updated