Description
Next.js is a React framework for building full-stack web applications. To mitigate CVE-2025-29927, Next.js validated the x-middleware-subrequest-id which persisted across multiple incoming requests. However, this subrequest ID is sent to all requests, even if the destination is not the same host as the Next.js application. Initiating a fetch request to a third-party within Middleware will send the x-middleware-subrequest-id to that third party. This vulnerability is fixed in 12.3.6, 13.5.10, 14.2.26, and 15.2.4.
CVSS Metrics
- Vector
- CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack Vector
- network
- Complexity
- high
- Privileges
- none
- User Action
- none
- Confidentiality
- undefined
- Integrity
- undefined
- Availability
- undefined
- Weaknesses
- CWE-200
Metadata
- Primary Vendor
- VERCEL
- Published
- 4/2/2025
- Last Modified
- 9/10/2025
- Source
- NIST NVD
- Note: Verify all details with official vendor sources before applying patches.
Affected Products
vercel : next.jsvercel : next.jsvercel : next.jsvercel : next.js
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