CVE-2026-44572

A flaw was found in Next.js. An external client could exploit this vulnerability by sending a x-nextjs-data header on a request to a path handled by middleware that returns a redirect. This action could cause the middleware or proxy to incorrectly process the request as a data request, replacing the standard Location redirect header with an internal x-nextjs-redirect header. If the application is deployed behind a caching Content Delivery Network (CDN) or reverse proxy, a malicious request could poison the cached redirect response, leading to a denial of service for subsequent visitors attempting to access the affected path.