XSS in Danny-Avila Librechat
CVE-2025-66452
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.
Vulnerability class: XSS (Cross-Site Scripting)
EPSS: 0.002 (8.3th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.1 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.
Affected products
- Danny-avila Librechat — versions <= 0.8.1
- Librechat
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)
Frequently asked questions
- What is CVE-2025-66452?
- CVE-2025-66452 is a medium-severity vulnerability in Danny-Avila Librechat, classified under Cross-site Scripting. CVSS score: 6.1/10. Published 2025-12-11.
- How severe is CVE-2025-66452?
- Medium severity. CVSS v3 base score is 6.1 out of 10.