danny-avila LibreChat up to 0.8.1 JSON Parser express.json cross site scripting

Summaryinfo

A vulnerability was found in danny-avila LibreChat up to 0.8.1. It has been classified as problematic. This affects the function express.json of the component JSON Parser. This manipulation causes cross site scripting. The identification of this vulnerability is CVE-2025-66452. It is possible to initiate the attack remotely. There is no exploit available.

Detailsinfo

A vulnerability has been found in danny-avila LibreChat up to 0.8.1 and classified as problematic. Affected by this vulnerability is the function express.json of the component JSON Parser. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2025-66452 since 12/01/2025. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1059.007 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Chat Software

Vendor

• danny-avila

Name

• LibreChat

Version

• 0.8.0
• 0.8.1

Website

• Product: https://github.com/danny-avila/LibreChat/

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