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.

NextChat versions from 2.15.8 through 2.16.1 contain an improper URL validation vulnerability in the proxy endpoint that allows attackers to obtain the server's OpenAI API key. The x-base-url header is validated using substring matching instead of hostname parsing, allowing any URL containing 'api.openai.com' to pass validation and receive the server's credentials in the Authorization header.

A weakness has been identified in ChatGPTNextWeb NextChat up to 2.16.1. This affects the function storeUrl of the file app/api/artifacts/route.ts of the component Artifacts Endpoint. This manipulation of the argument ID causes server-side request forgery. It is possible to initiate the attack remotely. The exploit has been made available to the public and could be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.

A security flaw has been discovered in ChatGPTNextWeb NextChat up to 2.16.1. Affected by this issue is the function proxyHandler of the file app/api/[provider]/[...path]/route.ts. The manipulation results in server-side request forgery. The attack may be performed from remote. The exploit has been released to the public and may be used for attacks. The project was informed of the problem early through an issue report but has not responded yet.