{"id":"CVE-2021-43803","aliases":["GHSA-25mp-g6fv-mqxx"],"url":"https://o3.security/vulnerability/CVE-2021-43803","summary":"Unexpected server crash in Next.js.","details":"Next.js is a React framework. In versions of Next.js prior to 12.0.5 or 11.1.3, invalid or malformed URLs could lead to a server crash. In order to be affected by this issue, the deployment must use Next.js versions above 11.1.0 and below 12.0.5, Node.js above 15.0.0, and next start or a custom server. Deployments on Vercel are not affected, along with similar environments where invalid requests are filtered before reaching Next.js. Versions 12.0.5 and 11.1.3 contain patches for this issue.","published":"2021-12-10T00:15:11.827Z","modified":"2026-07-09T11:24:02.172664Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"next","fixedVersion":"12.0.5"},{"ecosystem":"npm","name":"next","fixedVersion":"11.1.3"}],"fix":{"url":"https://github.com/vercel/next.js/commit/6d98b4fb4315dec1badecf0e9bdc212a4272b264","label":"vercel/next.js@6d98b4f"},"references":[{"type":"ADVISORY","url":"https://github.com/vercel/next.js/releases/tag/v11.1.3"},{"type":"ADVISORY","url":"https://github.com/vercel/next.js/releases/v12.0.5"},{"type":"FIX","url":"https://github.com/vercel/next.js/commit/6d98b4fb4315dec1badecf0e9bdc212a4272b264"},{"type":"FIX","url":"https://github.com/vercel/next.js/pull/32080"},{"type":"FIX","url":"https://github.com/vercel/next.js/security/advisories/GHSA-25mp-g6fv-mqxx"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-09T11:24:02.172664Z"}}