{"cve":"CVE-2022-21721","nvd":{"published":"2022-01-28T22:15:16.360","modified":"2026-06-17T04:26:51.300","status":"Modified","description":"Next.js is a React framework. Starting with version 12.0.0 and prior to version 12.0.9, vulnerable code could allow a bad actor to trigger a denial of service attack for anyone using i18n functionality. In order to be affected by this CVE, one must use next start or a custom server and the built-in i18n support. Deployments on Vercel, along with similar environments where invalid requests are filtered before reaching Next.js, are not affected. A patch has been released, `next@12.0.9`, that mitigates this issue. As a workaround, one may ensure `/${locale}/_next/` is blocked from reaching the Next.js instance until it becomes feasible to upgrade.","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":[],"references":["https://github.com/vercel/next.js/pull/33503","https://github.com/vercel/next.js/releases/tag/v12.0.9","https://github.com/vercel/next.js/security/advisories/GHSA-wr66-vrwm-5g5x","https://github.com/vercel/next.js/pull/33503","https://github.com/vercel/next.js/releases/tag/v12.0.9"],"products":["vercel:next.js"],"source":"nvd","synced_at":"2026-10-19T21:27:20.926095847+00:00"},"epss":{"cve":"CVE-2022-21721","score":0.02153,"percentile":0.82161,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-wr66-vrwm-5g5x","url":"https://osv.dev/vulnerability/GHSA-wr66-vrwm-5g5x","summary":"Denial of Service Vulnerability in next.js","modified":"2026-09-10T03:49:11.471300399Z","packages":[{"ecosystem":"npm","name":"next","purl":"pkg:npm/next","ranges":[">=12.0.0 <12.0.9"],"fixed":["12.0.9"]}]}],"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."]}