What was the Next.js middleware vulnerability?

CVE-2025-29927 let a crafted header skip middleware, exposing apps whose only auth check lived there. It is fixed in patched versions.

The redirect that let them in

Q: Is middleware enough to protect my pages?

No. Middleware is a useful place for redirects, but it is a single layer, and framework bugs have allowed requests to skip it. Check authorization again wherever data is read: in server pages, route handlers and database rules. Keep your framework patched.

Your sends signed-out visitors to the login page. A security advisory says one extra header can skip middleware entirely.

This answers: Is middleware enough to protect my pages? No coding needed. 2 quick decisions.

Who may see what
Who is signed in

Checking your access…

Is middleware enough to protect my pages?

No. is a useful place for redirects, but it is a single layer, and framework bugs have allowed requests to skip it. Check authorization again wherever data is read: in server pages, route handlers and database rules. Keep your framework patched.

Trail of the bug

Breaks at Your server: Proxy skipped; nothing else checks

Why AI tools write this bug

Templates often put the only sign-in check in because it protects every route with a few lines of code.

How to fix it

Check access in each server page and .

3 more steps, and a prompt that checks your own app for this bug. Part of Pro.

Unlock

Common questions

What was the Next.js middleware vulnerability?: CVE-2025-29927 let a crafted header skip middleware, exposing apps whose only auth check lived there. It is fixed in patched versions.

The redirect that let them in

Your sends signed-out visitors to the login page. A security advisory says one extra header can skip middleware entirely.

This answers: Is middleware enough to protect my pages? No coding needed. 2 quick decisions.

Who may see what
Who is signed in

Sign in to walk this one

2 decisions, about 4 minutes, and a prompt to check your own app for the same problem.

Checking your access…

Is middleware enough to protect my pages?

Trail of the bug

Breaks at Your server: Proxy skipped; nothing else checks

Why AI tools write this bug

Templates often put the only sign-in check in because it protects every route with a few lines of code.

How to fix it

Check access in each server page and .

3 more steps, and a prompt that checks your own app for this bug. Part of Pro.

Unlock

How to fix it

Check access in each server page and .

3 more steps, and a prompt that checks your own app for this bug. Part of Pro.

Unlock

Common questions

What was the Next.js middleware vulnerability?: CVE-2025-29927 let a crafted header skip middleware, exposing apps whose only auth check lived there. It is fixed in patched versions.