{"id":"GHSA-267c-6grr-h53f","revision":"6b649cd2011e4410be326f239bfa9bcd","records":[{"revision":"6b649cd2011e4410be326f239bfa9bcd","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-267c-6grr-h53f","aliases":["CVE-2026-44575"],"title":"Next.js has a Middleware / Proxy bypass in App Router applications via segment-prefetch routes","description":"### Impact\n\nApp Router applications that rely on middleware or proxy-based checks for authorization can allow unauthorized access through transport-specific route variants used for segment prefetching. In affected configurations, specially crafted `.rsc` and segment-prefetch URLs can resolve to the same page without being matched by the intended middleware rule, which can allow protected content to be reached without the expected authorization check.\n\n### Fix\n\nWe now include App Router transport variants when generating middleware matchers, so middleware protections are applied consistently to those requests as well as to the normal page URL.\n\n### Workarounds\n\nIf you cannot upgrade immediately, enforce authorization in the underlying route or page logic instead of relying solely on middleware.","state":0,"publishedAt":"2026-05-11T15:54:24+00:00","modifiedAt":"2026-09-10T03:51:03.9709007+00:00","affected":[{"ecosystem":"npm","name":"next","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"15.2.0"},{"kind":"fixed","version":"15.5.16"}]}],"versions":[],"rawVersionEvidence":null},{"ecosystem":"npm","name":"next","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"16.0.0"},{"kind":"fixed","version":"16.2.5"}]}],"versions":[],"rawVersionEvidence":null}],"metrics":[{"system":"CVSS_V3","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","score":null,"severity":null},{"system":"Publisher rating","vector":null,"score":null,"severity":"HIGH"}],"references":["https://github.com/vercel/next.js/security/advisories/GHSA-267c-6grr-h53f","https://nvd.nist.gov/vuln/detail/CVE-2026-44575","https://github.com/vercel/next.js","https://github.com/vercel/next.js/releases/tag/v15.5.16","https://github.com/vercel/next.js/releases/tag/v16.2.5"],"sourceUrl":"https://github.com/advisories/GHSA-267c-6grr-h53f","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-267c-6grr-h53f","identifiers":["GHSA-267c-6grr-h53f","CVE-2026-44575"]},"retained":false,"historicalAffected":[]}],"coverage":[]}