Description

Next.js is a React framework for building full-stack web applications. Prior to 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 14.2.25 and 15.2.3.

Classification

CVE ID: CVE-2025-29927

CVSS Base Severity: CRITICAL

CVSS Base Score: 9.1

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected Products

Vendor: vercel

Product: next.js

Nuclei Template

http/cves/2025/CVE-2025-29927.yaml

Exploit Prediction Scoring System (EPSS)

EPSS Score: 91.42% (probability of being exploited)

EPSS Percentile: 99.63% (scored less or equal to compared to others)

EPSS Date: 2025-04-18 (when was this score calculated)

References

https://nvd.nist.gov/vuln/detail/CVE-2025-29927
https://github.com/vercel/next.js/security/advisories/GHSA-f82v-jwr5-mffw

Timeline