CVE-2026-64642 Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale
Attackers can bypass middleware authentication in Next.js App Router applications using Turbopack with a single locale configuration.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64642?
CVE-2026-64642 is a high-severity authentication bypass vulnerability in Vercel Next.js, published on 27 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Next.js is a React framework for building full-stack web applications. In versions 16.0.0 through 16.2.10, crafted requests targeting Next.js applications using App Router built with Turbopack and a single entry in config.i18n.locales can bypass middleware/proxy based authentication. This issue has been fixed in version 16.2.11.
Weakness: CWE-285
Which versions are affected by CVE-2026-64642?
2 open source packages ship an affected version, including next. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
next npm | From 16.0.0 | 16.2.11 |
next npm | From 16.0.0 | 16.2.11 |
Products include Vercel Next.js.
How do I fix CVE-2026-64642?
Upgrade next to 16.2.11 or later.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-64642 being exploited?
There is no known exploitation of CVE-2026-64642 in the wild and no public exploit code.
Other vulnerabilities in Vercel Next.js
- CVE-2025-29927 Authorization Bypass in Next.js Middleware
- CVE-2026-44578 Next.js: Server-side request forgery in applications using WebSocket upgrades
- CVE-2026-94483 Next.js: Server-Side Request Forgery in Image Optimization
- CVE-2026-64645 Next.js: Server-Side Request Forgery in rewrites via attacker-controlled destination hostname
- CVE-2026-64649 Next.js: Server-Side Request Forgery in Server Actions on Custom Servers
Sources
Also known as CLEANSTART-2026-FI73865, CLEANSTART-2026-GC88810, ECHO-6bda-043c-2bec, GHSA-6gpp-xcg3-4w24, MINI-9wvx-hc9f-6c35, MINI-c8h8-whv8-5rf4 and 2 more.