CVE-2026-94486: CWE-346: Origin Validation Error in vercel next.js
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.
CVE-2026-94486: CWE-346: Origin Validation Error in vercel next.js
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.
CVSS v4.0
Score 2.3low
Affected software
vercel
next.js
Weaknesses
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-09-21T17:25:42.292Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6abfce5fa43b0b3b89cf6dfc
Added to database: 10/02/2026, 15:31:43 UTC
Last updated: 10/02/2026, 15:31:43 UTC
Views: 1
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