{"cve":"CVE-2021-43803","nvd":{"published":"2021-12-10T00:15:11.827","modified":"2026-06-17T04:11:28.210","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-20"],"references":["https://github.com/vercel/next.js/commit/6d98b4fb4315dec1badecf0e9bdc212a4272b264","https://github.com/vercel/next.js/pull/32080","https://github.com/vercel/next.js/releases/tag/v11.1.3","https://github.com/vercel/next.js/releases/v12.0.5","https://github.com/vercel/next.js/security/advisories/GHSA-25mp-g6fv-mqxx"],"products":["vercel:next.js"],"source":"nvd","synced_at":"2026-10-19T21:25:41.256909649+00:00"},"epss":{"cve":"CVE-2021-43803","score":0.47254,"percentile":0.98838,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-25mp-g6fv-mqxx","url":"https://osv.dev/vulnerability/GHSA-25mp-g6fv-mqxx","summary":"Unexpected server crash in Next.js.","modified":"2026-07-08T06:29:22.632770062Z","packages":[{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=12.0.0 <12.0.5"],"fixed":["12.0.5"]},{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=0.9.9 <11.1.3"],"fixed":["11.1.3"]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}