CVE-2026-64644 Next.js: Denial of Service in the Image Optimization API using SVGs
Attackers can cause CPU exhaustion in Next.js Image Optimization API via malicious remote SVGs when remote image optimization is enabled.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-64644?
CVE-2026-64644 is a medium-severity denial of service 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 15.5.0 through 15.5.20 and 16.0.0 through 16.2.10, when self-hosting Next.js with the default image loader, the Image Optimization API can optimize remotely hosted images if configured (not enabled by default). If those images contain malicious content, they can cause CPU exhaustion in /_next/image endpoints.Only config.images.remotePatterns is affected, and just the patterns in that array, whereas config.images.unoptimized: true, config.images.loader: 'custom', and Vercel are not impacted. This issue has been fixed in versions 15.5.21 and 16.2.11.
Weakness: CWE-407
Which versions are affected by CVE-2026-64644?
4 open source packages ship an affected version, including next. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
next npm | From 15.5.0 | 15.5.21 |
next npm | From 15.5.0 | 15.5.21 |
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-2026-64644?
Upgrade next to a fixed version for your release line: 15.5.21 or 16.2.11.
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-2026-64644 being exploited?
There is no known exploitation of CVE-2026-64644 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-LH73622, CLEANSTART-2026-VX56727, ECHO-4e9d-a9c7-9b65, GHSA-q8wf-6r8g-63ch, MINI-89cg-hj9f-5w3x, MINI-9fph-3qg3-8hrr and 3 more.