CVE-2026-103004 next.js cache leak on warm `use cache` handlers accessing root param
Next.js cache keying flaw allows leaking cached content across different root parameters when Cache Components are 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-2026-103004?
CVE-2026-103004 is a medium-severity vulnerability in Vercel Next.js, published on 1 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Next.js versions from 16.3.0 to 16.3.7 warm `use cache` handlers using `next/root-params` and can leak their return value to pages with different root params. With Cache Components enabled (cacheComponents: true), a 'use cache' function that calls another 'use cache' function that reads a root param can be keyed incorrectly when the inner call is served from an existing entry: the enclosing function's cache key then omits that root param. The enclosing entry is written once and reused for all root param values, so a response for one root param value can serve content produced for a different value — whether the page is prerendered at build time or at runtime, or rendered dynamically. Shared cache headers let downstream caches redistribute the content further.
What values are leaked cannot be attacker controlled. Which value's content is served depends only on which invocation wrote the entry first.
This has been patched in 16.3.8.
Weakness: CWE-524
Which versions are affected by CVE-2026-103004?
2 open source packages ship an affected version, including next. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
next npm | From 16.3.0 | 16.3.8 |
next npm | From 16.3.0 | 16.3.8 |
Products include Vercel Next.js.
How do I fix CVE-2026-103004?
Upgrade next to 16.3.8 or later.
Is CVE-2026-103004 being exploited?
There is no known exploitation of CVE-2026-103004 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-MS47438, CLEANSTART-2026-SE76644, GHSA-h694-7cp9-m8p3.