CVE-2025-29927 PoC — Authorization Bypass in Next.js Middleware

Source

https://github.com/0xPb1/Next.js-CVE-2025-29927

Associated Vulnerability

Title: Authorization Bypass in Next.js Middleware (CVE-2025-29927)
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.

Readme

# Next.js Docker Demo

A simple Hello World application built with Next.js 12.2 and Docker.

## Prerequisites

- Docker installed on your system
- Node.js 16 or later (for local development)

## Building the Docker Image

To build the Docker image, run:

```bash
docker build -t nextjs-docker-demo .
```

## Running the Container

To run the container, use:

```bash
docker run -p 3000:3000 nextjs-docker-demo
```

The application will be available at http://localhost:3000

## Development

For local development without Docker:

1. Install dependencies:
```bash
npm install
```

2. Run the development server:
```bash
npm run dev
```

The application will be available at http://localhost:3000

File Snapshot

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