Next.js is a React framework for building full-stack web applications. Prior to 14.2.25 and 15.2.3, it is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware. If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application. This vulnerability is fixed in 14.2.25 and 15.2.3.

Next.js is a React framework for building full-stack web applications. Starting in version 1.11.4 and prior to versions 12.3.5, 13.5.9, 14.2.25, and 15.2.3, it is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware. If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application. This vulnerability is fixed in 12.3.5, 13.5.9, 14.2.25, and 15.2.3.

https://github.com/vercel/next.js/commit/52a078da3884efe6501613c7834a3d02a91676d2

https://github.com/vercel/next.js/commit/5fd3ae8f8542677c6294f32d18022731eab6fe48

https://github.com/vercel/next.js/releases/tag/v12.3.5

https://github.com/vercel/next.js/releases/tag/v13.5.9