JSON Parsing Error Handling in LibreChat by Danny Avila
CVE-2025-66452

5.3MEDIUM

Key Information:

Vendor

Danny-avila

Status
Librechat
Vendor
CVE Published:
11 December 2025

What is CVE-2025-66452?

In LibreChat versions up to 0.8.0, a lack of proper error handling for JSON parsing can expose user input errors in error messages. When the express.json() method encounters a SyntaxError, it includes user input that could be HTML or JavaScript, potentially leading to Cross-Site Scripting (XSS) vulnerabilities if strict Content-Type headers are not enforced. This exposure allows attackers to inject harmful scripts that can be reflected in responses, posing a serious security risk.

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Affected Version(s)

LibreChat <= 0.8.1

References

https://github.com/danny-avila/LibreChat/security/advisor...
x_refsource_CONFIRM

CVSS V4

Score:
5.3
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

JSON
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