CVE-2026-118132: XSS
NextChat version 2.16.1 contains a client‑side cross‑site scripting (XSS) vulnerability in the Plugin Editor due to unsafe rendering of externally supplied OpenAPI plugin schema content. When a plugin schema is loaded from a remote URL, the returned content is stored in plugin.content and later rendered using React’s dangerouslySetInnerHTML without proper sanitization. An attacker can host a malicious OpenAPI schema containing HTML or JavaScript markup and trick a user into loading it through the Plugin Editor, resulting in arbitrary JavaScript execution in the NextChat origin. Successful exploitation allows access to JavaScript‑readable cookies and other client‑side data associated with the NextChat application.
Affected Software
Event History
Frequently Asked Questions
Who is exposed to this issue?
Users of NextChat 2.16.1 who load an OpenAPI plugin schema from a remote URL through the Plugin Editor are exposed. The malicious schema must be loaded into the user's browser for the script to execute in the NextChat origin.
What does an attacker need to exploit it?
An attacker needs to host a malicious OpenAPI schema containing HTML or JavaScript markup and persuade a user to load that schema through the Plugin Editor. The issue is triggered by unsafe rendering of the remotely supplied schema content.
What could an attacker access after successful exploitation?
Successful exploitation enables arbitrary JavaScript execution in the NextChat origin. This can expose JavaScript-readable cookies and other client-side data associated with the application.
What can be done while a fix is unavailable?
Avoid loading OpenAPI plugin schemas from untrusted or unknown remote URLs in the Plugin Editor. Only load schemas from sources you trust and have reviewed.