CVSS 4.0
1.7 lowCVSS: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:UCVE-2025-30218
Low (1.7) in vercel next.js. EPSS 0.4% chance of exploitation in the next 30 days. Fixed in next 12.3.6, 13.5.10, 14.2.26.
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.
Severity
CVSS 3.1
5.9 mediumCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N- EPSS
- 0.4% chance of exploitation in the next 30 days; higher than 37% of CVEs (scores of 2026-10-31)
- CWE
- CWE-200
- Published
- Modified
- Record from
- the NVD, synced
Affected
- vercel:next.js
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-223j-4rm8-mrmf | npm | next | >=12.3.5 <12.3.6 | 12.3.6 |
| GHSA-223j-4rm8-mrmf | npm | next | >=13.5.9 <13.5.10 | 13.5.10 |
| GHSA-223j-4rm8-mrmf | npm | next | >=14.2.25 <14.2.26 | 14.2.26 |
| GHSA-223j-4rm8-mrmf | npm | next | >=15.2.3 <15.2.4 | 15.2.4 |