{"id":"GHSA-36qx-fr4f-26g5","revision":"68c8cc0c80504050a622bd72bbfd52c4","records":[{"revision":"68c8cc0c80504050a622bd72bbfd52c4","observedAt":"2026-10-24T13:17:17.793+00:00","statement":{"source":"osv","id":"GHSA-36qx-fr4f-26g5","aliases":["CVE-2026-44573"],"title":"Next.js has a Middleware / Proxy bypass in Pages Router applications using i18n","description":"### Impact\n\nApplications using the Pages Router with `i18n` configured and middleware/proxy-based authorization can allow unauthorized access to protected page data through locale-less `/_next/data/<buildId>/<page>.json` requests. In affected configurations, middleware does not run for the unprefixed data route, allowing an attacker to retrieve SSR JSON for protected pages without passing the intended authorization checks.\n\n### Fix\nThe matcher logic was updated to perform the same match as it would on a non-i18n data route.\n\n### Workarounds\n\nIf you cannot upgrade immediately, enforce authorization in the page's server-side data path instead of relying solely on middleware.","state":0,"publishedAt":"2026-05-11T15:53:51+00:00","modifiedAt":"2026-09-10T03:51:04.325298+00:00","affected":[{"ecosystem":"npm","name":"next","ranges":[{"type":"SEMVER","events":[{"kind":"introduced","version":"12.2.0"},{"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-36qx-fr4f-26g5","https://nvd.nist.gov/vuln/detail/CVE-2026-44573","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-36qx-fr4f-26g5","license":"GitHub Advisory Database · CC-BY-4.0","key":"osv:GHSA-36qx-fr4f-26g5","identifiers":["GHSA-36qx-fr4f-26g5","CVE-2026-44573"]},"retained":false,"historicalAffected":[]}],"coverage":[]}