{"id":"CVE-2022-21681","aliases":["GHSA-5v2h-r2cx-5xgj"],"url":"https://o3.security/vulnerability/CVE-2022-21681","summary":"Exponential catastrophic backtracking (ReDoS) in marked","details":"### Impact\n\n_What kind of vulnerability is it?_\n\nDenial of service.\n\nThe regular expression `inline.reflinkSearch` may cause catastrophic backtracking against some strings.\nPoC is the following.\n\n```javascript\nimport * as marked from 'marked';\n\nconsole.log(marked.parse(`[x]: x\n\n\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](\\\\[\\\\](`));\n```\n\n_Who is impacted?_\n\nAnyone who runs untrusted markdown through marked and does not use a worker with a time limit.\n\n### Patches\n\n_Has the problem been patched?_\n\nYes\n\n_What versions should users upgrade to?_\n\n4.0.10\n\n### Workarounds\n\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nDo not run untrusted markdown through marked or run marked on a [worker](https://marked.js.org/using_advanced#workers) thread and set a reasonable time limit to prevent draining resources.\n\n### References\n\n_Are there any links users can visit to find out more?_\n\n- https://marked.js.org/using_advanced#workers\n- https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n* Open an issue in [marked](https://github.com/markedjs/marked)\n","published":"2022-01-14T00:00:00Z","modified":"2026-08-12T03:51:41.872945324Z","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":1,"affectedPackages":[{"ecosystem":"npm","name":"marked","fixedVersion":"4.0.10"}],"fix":{"url":"https://github.com/markedjs/marked/commit/8f806573a3f6c6b7a39b8cdb66ab5ebb8d55a5f5","label":"markedjs/marked@8f80657"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/21xxx/CVE-2022-21681.json"},{"type":"ADVISORY","url":"https://github.com/markedjs/marked/security/advisories/GHSA-5v2h-r2cx-5xgj"},{"type":"ADVISORY","url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AIXDMC3CSHYW3YWVSQOXAWLUYQHAO5UX/"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2022-21681"},{"type":"FIX","url":"https://github.com/markedjs/marked/commit/8f806573a3f6c6b7a39b8cdb66ab5ebb8d55a5f5"},{"type":"WEB","url":"https://github.com/markedjs/marked/commit/c4a3ccd344b6929afa8a1d50ac54a721e57012c0"},{"type":"PACKAGE","url":"https://github.com/markedjs/marked"},{"type":"WEB","url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/AIXDMC3CSHYW3YWVSQOXAWLUYQHAO5UX"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:41.872945324Z"}}