CVE-2026-94486 Next.js: Information disclosure in the Next.js development server's Model Context Protocol endpoint
A malicious website can access the Next.js development server's MCP endpoint to read source code, logs, and project details, affecting developers using the dev server.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-94486?
CVE-2026-94486 is a low-severity vulnerability in Vercel Next.js, published on 2 Oct 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Next.js is a React framework for building full-stack web applications. From 16.0.0 until 16.3.8, the next dev development server exposes a Model Context Protocol endpoint without reliably restricting cross-site requests. A malicious website visited by a developer can reach the endpoint and read the project's disk location, source code snippets from error reports, route inventory, and development logs. Production deployments do not serve this endpoint. This issue is fixed in version 16.3.8.
Weakness: CWE-346
Which versions are affected by CVE-2026-94486?
2 open source packages ship an affected version, including next. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
next npm | From 16.0.0 | 16.3.8 |
next npm | From 16.0.0 | 16.3.8 |
Products include Vercel Next.js.
How do I fix CVE-2026-94486?
Upgrade next to 16.3.8 or later.
Is CVE-2026-94486 being exploited?
There is no known exploitation of CVE-2026-94486 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-AM63007, CLEANSTART-2026-IB88795, CLEANSTART-2026-NT97778, CLEANSTART-2026-ZH20233, ECHO-de4e-a8b3-75ff, GHSA-39w2-rjm5-chcv and 3 more.