# CVE-2026-94486: Vercel Next.js information disclosure in dev server MCP endpoint

Source: https://junglewise.ai/threats/cve-2026-94486-next-js-is-a-react-framework-for-building-full-stack-web  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-02. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-94486 · Severity: medium · CVSS 5.4 · Published 2026-10-02

Next.js is a React framework used to build web applications. The development server in versions 16.0.0 through 16.3.7 exposes a Model Context Protocol endpoint that insufficiently restricts cross-site requests. A malicious website visited by a developer can steal sensitive information including the project's disk location, source code snippets, route inventory, and development logs. Production deployments are not affected.

Technologies: [next (npm)](https://junglewise.ai/threats/technologies/npm-next), [Vercel Next.js](https://junglewise.ai/threats/technologies/next-js). Vendors: [npm](https://junglewise.ai/threats/vendors/npm), [Vercel](https://junglewise.ai/threats/vendors/vercel).

## Quick answers

**Is CVE-2026-94486 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-94486 being exploited in the wild.

**How severe is CVE-2026-94486?** Medium severity, with a CVSS score of 5.4, published 2 October 2026.

**Which products and versions are affected?** next (npm) >= 16.0.0, < 16.3.8, SEMVER:introduced=16.0.0,fixed=16.3.8; Vercel Next.js 16.0.0 to 16.3.7.

**Is there a fix for CVE-2026-94486?** Yes. next (npm): upgrade to 16.3.8 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-94486 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-94486?** Check whether you run next (npm) or Vercel Next.js at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- next (npm): upgrade to 16.3.8 or later

  ```sh
  npm install next@16.3.8
  ```


## Technical details

A cross-site request forgery (CSRF) vulnerability exists in the Next.js development server's Model Context Protocol endpoint, which lacks reliable same-origin protections. An attacker can craft a malicious web page that, when visited by a developer running next dev locally, makes requests to the exposed endpoint via the browser to extract sensitive development information. The vulnerability requires a developer to visit an attacker-controlled website while running the development server; production deployments do not expose this endpoint.

## Affected products

- Vercel Next.js 16.0.0 to 16.3.7

## Identifiers

- CVE-2026-94486
- GHSA-39w2-rjm5-chcv

## Timeline

- 2026-10-02: disclosed

## References

- [https://github.com/vercel/next.js/commit/2d9f50a409312696145b82b3157aadb6b1fef476](https://github.com/vercel/next.js/commit/2d9f50a409312696145b82b3157aadb6b1fef476)
- [https://github.com/vercel/next.js/releases/tag/v16.3.8](https://github.com/vercel/next.js/releases/tag/v16.3.8)

## Related threats

- [Vercel Next.js remote code execution in use cache functions](https://junglewise.ai/threats/next-js-unauthenticated-remote-code-execution-in-use-cache-functions-ac3e73d3)
- [Next.js denial of service in App Router with Server Actions](https://junglewise.ai/threats/cve-2026-94482-next-js-denial-of-service-in-app-router-using-server-actions)
- [Next.js unauthenticated remote code execution in Image Optimization API](https://junglewise.ai/threats/next-js-unauthenticated-remote-code-execution-in-image-optimization-api-f1b22a87)
- [Next.js information disclosure in Draft Mode via use cache](https://junglewise.ai/threats/cve-2026-94544-next-js-is-a-react-framework-for-building-full-stack-web)
- [Next.js Pages Router response cache key bypass](https://junglewise.ai/threats/cve-2026-94543-next-js-is-a-react-framework-for-building-full-stack-web)