What’s Vulnerable › Vulnerabilities

CVE-2026-94486: Next.js: Information disclosure in the Next.js development server's Model Context Protocol endpoint

• Severity: medium (CVSS 5.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.1% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-02 · updated 2026-10-05
• Weakness: CWE-346

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.

Affected products

• Next.js: from 16.0.0 before 16.3.8 — fixed in 16.3.8

How to fix

Upgrade to a fixed version: Next.js 16.3.8. Check the vendor advisory for mitigations.

References

• 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/security/advisories/GHSA-39w2-rjm5-chcv

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