Next.js: Middleware / Proxy bypass through dynamic route parameter injection
Title source: cnaExploitation Summary
EIP tracks 2 public exploits for CVE-2026-44574. PoCs published by dwisiswant0, XZ1r0.
AI-analyzed exploit summary This repository contains functional proof-of-concept exploits for multiple Next.js vulnerabilities, including CVE-2026-44574, which involves a dynamic-route and middleware mismatch. The PoCs are well-documented with detailed write-ups, vulnerable code excerpts, and runnable exploit scripts.
Description
Next.js is a React framework for building full-stack web applications. From 15.4.0 to before 15.5.16 and 16.2.5, applications that rely on middleware to protect dynamic routes can be vulnerable to authorization bypass. In affected deployments, specially crafted query parameters can alter the dynamic route value seen by the page while leaving the visible path unchanged, which can allow protected content to be rendered without passing the expected middleware check. This vulnerability is fixed in 15.5.16 and 16.2.5.
Exploits (2)
This repository contains functional proof-of-concept exploits for multiple Next.js vulnerabilities, including CVE-2026-44574, which involves a dynamic-route and middleware mismatch. The PoCs are well-documented with detailed write-ups, vulnerable code excerpts, and runnable exploit scripts.
This repository contains a functional exploit for CVE-2026-44574, demonstrating a dynamic-route parameter injection bypass in Next.js ≤16.2.4. The exploit leverages internal search parameters (`nxtP*`) and a double-encoding bug to bypass middleware authorization checks, allowing unauthorized access to protected routes.
References (1)
Scores
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N