CVE-2026-44576 Next.js: Cache poisoning in React Server Component responses
Attackers can poison shared caches to serve incorrect React Server Component payloads to visitors, requiring specific cache partitioning configurations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-44576?
CVE-2026-44576 is a medium-severity 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 14.2.0 to before 15.5.16 and 16.2.5, applications using React Server Components can be vulnerable to cache poisoning when shared caches do not correctly partition response variants. Under affected conditions, an attacker can cause an RSC response to be served from the original URL and poison shared cache entries so later visitors receive component payloads instead of the expected HTML. This vulnerability is fixed in 15.5.16 and 16.2.5.
Weakness: CWE-436
Which versions are affected by CVE-2026-44576?
4 open source packages ship an affected version, including next. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
next npm | From 14.2.0 | 15.5.16 |
next npm | From 14.2.0 | 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-2026-44576?
Upgrade next to a fixed version for your release line: 15.5.16 or 16.2.5.
Is CVE-2026-44576 being exploited?
There is no known exploitation of CVE-2026-44576 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-GL78918, CLEANSTART-2026-ML50911, GHSA-wfc6-r584-vfw7, MINI-f6rj-93mg-w2f4, MINI-hg8x-q5hj-m4h4, MINI-hrwg-5fq8-3qx2 and 2 more.