CVE-2025-29927

★ CVE-2025-29927 Next.js middleware bypass PoC ★

Description

CVE-2025-29927 : Next.js middleware bypass PoC description: 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.

Lab setup

cd next15
docker build --tag nextjs .
docker run -p 3000:3000 -it --rm nextjs

How to use

Git clone

git clone https://github.com/EQSTLab/CVE-2025-29927.git
cd CVE-2025-29927

Command

chmod +x poc.sh
./poc.sh

Output