CVE-2026-44572
Next.js is a React framework for building full-stack web applications.
Impact
Next.js is a React framework for building full-stack web applications. From 12.2.0 to before 15.5.16 and 16.2.5, an external client could send a x-nextjs-data header on a normal request to a path handled by middleware that returns a redirect. When that happened, the middleware/proxy could treat the request as a data request and replace the standard Location redirect header with the internal x-nextjs-redirect header. Browsers do not follow x-nextjs-redirect, so the response became an unusable redirect for normal clients. If the application was deployed behind a CDN or reverse proxy that caches 3xx responses without varying on this header, a single attacker request could poison the cached redirect response for the affected path. Subsequent visitors could then receive a cached redirect response without a Location header, causing a denial of service for that redirect path until the cache entry expired or was purged. This vulnerability is fixed in 15.5.16 and 16.2.5.
Affected packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | next | >= 12.2.0, < 15.5.16 | 15.5.16 |
Affected products
| Vendor | Product | Affected versions |
|---|---|---|
| Vercel | Next.Js | from 12.2.0 before 15.5.16 from 16.0.0 before 16.2.5 |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-3g8h-86w9-wvmq
- https://github.com/vercel/next.js/security/advisories/GHSA-3g8h-86w9-wvmq
- https://github.com/vercel/next.js/releases/tag/v15.5.16
- https://github.com/vercel/next.js/releases/tag/v16.2.5
- https://nvd.nist.gov/vuln/detail/CVE-2026-44572