Vulnerability Description
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.
CVSS Score
LOW
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Vercel | Next.Js | >= 12.2.0, < 15.5.16 |
Related Weaknesses (CWE)
References
- https://github.com/vercel/next.js/security/advisories/GHSA-3g8h-86w9-wvmqMitigationVendor Advisory
FAQ
What is CVE-2026-44572?
CVE-2026-44572 is a vulnerability with a CVSS score of 3.7 (LOW). 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 hand...
How severe is CVE-2026-44572?
CVE-2026-44572 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-44572?
Check the references section above for vendor advisories and patch information. Affected products include: Vercel Next.Js.