CVE-2025-30218
Fixed upstream EPSS <1%CVSS 1.7
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.
Products: vercel next.js
Fixed upstream
| Ecosystem | Package | Fixed in |
|---|---|---|
| npm | next | 12.3.6 |
| npm | next | 13.5.10 |
| npm | next | 14.2.26 |
| npm | next | 15.2.4 |