Authorization Bypass in Next.js Middleware
Vulnerability Description
Next.js is a React framework for building full-stack web applications. Starting in version 1.11.4 and prior to versions 12.3.5, 13.5.9, 14.2.25, and 15.2.3, it is possible to bypass authorization checks within a Next.js application, if the authorization check occurs in middleware. If patching to a safe version is infeasible, it is recommend that you prevent external user requests which contain the x-middleware-subrequest header from reaching your Next.js application. This vulnerability is fixed in 12.3.5, 13.5.9, 14.2.25, and 15.2.3.
Impact Analysis
Refer to official advisory for detailed impact metrics.
Remediation
Ensure systems are updated to the latest vendor-supplied patch levels.
Am I Vulnerable?
Launch our assessment wizard to check if your infrastructure is exposed to • CVE-2025-29927
Credits & Attribution
No credits recorded in the NVD database.
References
- https://github.com/vercel/next.js/security/advisories/GHSA-f82v-jwr5-mffw
- https://github.com/vercel/next.js/commit/52a078da3884efe6501613c7834a3d02a91676d2
- https://github.com/vercel/next.js/commit/5fd3ae8f8542677c6294f32d18022731eab6fe48
- https://github.com/vercel/next.js/releases/tag/v12.3.5
- https://github.com/vercel/next.js/releases/tag/v13.5.9
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