CVE-2026-44572 Next.js: Middleware / Proxy redirects can be cache-poisoned
Attackers can poison CDN caches via crafted headers, causing denial of service for redirect paths in Next.js applications behind caching proxies.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44572?
CVE-2026-44572 is a low-severity denial of service vulnerability in Vercel Next.js, published on 13 May 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. From 12.2.0 to before 15.5.16 and 16.2.5, an external client could send a x-nextjs-data header on a normal request to a path handled by middleware that returns a redirect. When that happened, the middleware/proxy could treat the request as a data request and replace the standard Location redirect header with the internal x-nextjs-redirect header. Browsers do not follow x-nextjs-redirect, so the response became an unusable redirect for normal clients. If the application was deployed behind a CDN or reverse proxy that caches 3xx responses without varying on this header, a single attacker request could poison the cached redirect response for the affected path. Subsequent visitors could then receive a cached redirect response without a Location header, causing a denial of service for that redirect path until the cache entry expired or was purged. This vulnerability is fixed in 15.5.16 and 16.2.5.
Weakness: CWE-349
Which versions are affected by CVE-2026-44572?
4 open source packages ship an affected version, including next. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
next npm | From 12.2.0 | 15.5.16 |
next npm | From 12.2.0 | 15.5.16 |
next npm | From 16.0.0 | 16.2.5 |
next npm | From 16.0.0 | 16.2.5 |
Products include Vercel Next.js.
How do I fix CVE-2026-44572?
Upgrade next to a fixed version for your release line: 15.5.16 or 16.2.5.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-44572 being exploited?
There is no known exploitation of CVE-2026-44572 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-2026-64642 Next.js: Middleware / Proxy bypass in App Router applications using Turbopack and single locale
- CVE-2026-64645 Next.js: Server-Side Request Forgery in rewrites via attacker-controlled destination hostname
Sources
Also known as CLEANSTART-2026-EY13226, CLEANSTART-2026-TC69199, GHSA-3g8h-86w9-wvmq, MINI-847r-r7jc-8864, MINI-gp28-34hr-7976, MINI-mcx2-cp43-vp45 and 2 more.