{"id":"CVE-2021-21306","aliases":["CLSA-2026-1784769550","EUVD-2021-0532","GHSA-4r62-v4vq-hr96"],"status":"published","title":"Denial of Service in Marked","description":"Marked is an open-source markdown parser and compiler (npm package \"marked\"). In marked from version 1.1.1 and before version 2.0.0, there is a Regular expression Denial of Service vulnerability. This vulnerability can affect anyone who runs user generated code through marked. This vulnerability is fixed in version 2.0.0.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.02492,"percentile":0.84887,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400"],"published":"2021-02-08T21:17:58Z","modified":"2026-10-20T10:54:28Z","fixes":[{"ecosystem":"npm","package":"marked","fixed_in":["2.0.0"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"marked","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.1.1"},{"fixed":"2.0.0"}]}]},{"source":"osv","ecosystem":"TuxCare:npm","package":"marked","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.2.7-tuxcare.0"},{"fixed":"1.2.7-tuxcare.1"}]}],"versions":["1.2.7"],"bundled":3},{"source":"osv","ecosystem":"npm","package":"marked","ranges":[{"type":"SEMVER","events":[{"introduced":"1.1.1"},{"fixed":"2.0.0"}]}]}],"products":[{"vendor":"marked_project","product":"marked"},{"vendor":"markedjs","product":"marked"}],"references":[{"url":"https://github.com/markedjs/marked/security/advisories/GHSA-4r62-v4vq-hr96","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/markedjs/marked/issues/1927","tags":["x_refsource_MISC","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/markedjs/marked/pull/1864","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://github.com/markedjs/marked/commit/7293251c438e3ee968970f7609f1a27f9007bccd","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web"]},{"url":"https://www.npmjs.com/package/marked","tags":["x_refsource_MISC","x_transferred","Product","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21306","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-4r62-v4vq-hr96"}],"sources":{"cve":[{"id":"CVE-2021-21306","title":"Denial of Service in Marked","description":"Marked is an open-source markdown parser and compiler (npm package \"marked\"). In marked from version 1.1.1 and before version 2.0.0, there is a Regular expression Denial of Service vulnerability. This vulnerability can affect anyone who runs user generated code through marked. This vulnerability is fixed in version 2.0.0.","status":"published","published":"2021-02-08T21:20:18Z","modified":"2024-08-03T18:09:15.882Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:32:59.802172Z"}],"euvd":[{"id":"EUVD-2021-0532","description":"Marked is an open-source markdown parser and compiler (npm package \"marked\"). In marked from version 1.1.1 and before version 2.0.0, there is a Regular expression Denial of Service vulnerability. This vulnerability can affect anyone who runs user generated code through marked. This vulnerability is fixed in version 2.0.0.","status":"published","published":"2021-02-08T21:20:18Z","modified":"2024-08-03T18:09:15Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-03T03:25:06.913643Z"}],"ghsa":[{"id":"GHSA-4r62-v4vq-hr96","title":"Regular Expression Denial of Service (REDoS) in Marked","description":"### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\n[Regular expression Denial of Service](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS)\n\nA Denial of Service attack can affect anyone who runs user generated code through `marked`.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\npatched in v2.0.0\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nNone.\n\n### References\n_Are there any links users can visit to find out more?_\n\nhttps://github.com/markedjs/marked/issues/1927\nhttps://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [marked](https://github.com/markedjs/marked/issues)","status":"published","published":"2021-02-08T21:17:58Z","modified":"2023-02-01T05:05:06Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:36:32.918681Z"}],"nvd":[{"id":"CVE-2021-21306","description":"Marked is an open-source markdown parser and compiler (npm package \"marked\"). In marked from version 1.1.1 and before version 2.0.0, there is a Regular expression Denial of Service vulnerability. This vulnerability can affect anyone who runs user generated code through marked. This vulnerability is fixed in version 2.0.0.","status":"published","published":"2021-02-08T22:15:12.45Z","modified":"2026-06-17T03:35:15.567Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:06:49.660551Z"}],"osv":[{"id":"CVE-2021-21306","description":"Marked is an open-source markdown parser and compiler (npm package \"marked\"). In marked from version 1.1.1 and before version 2.0.0, there is a Regular expression Denial of Service vulnerability. This vulnerability can affect anyone who runs user generated code through marked. This vulnerability is fixed in version 2.0.0.","status":"published","published":"2021-02-08T22:15:12.45Z","modified":"2026-10-20T10:54:28.017234849Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:18.004149Z"},{"id":"GHSA-4r62-v4vq-hr96","title":"Regular Expression Denial of Service (REDoS) in Marked","description":"### Impact\n_What kind of vulnerability is it? Who is impacted?_\n\n[Regular expression Denial of Service](https://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS)\n\nA Denial of Service attack can affect anyone who runs user generated code through `marked`.\n\n### Patches\n_Has the problem been patched? What versions should users upgrade to?_\n\npatched in v2.0.0\n\n### Workarounds\n_Is there a way for users to fix or remediate the vulnerability without upgrading?_\n\nNone.\n\n### References\n_Are there any links users can visit to find out more?_\n\nhttps://github.com/markedjs/marked/issues/1927\nhttps://owasp.org/www-community/attacks/Regular_expression_Denial_of_Service_-_ReDoS\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Open an issue in [marked](https://github.com/markedjs/marked/issues)","status":"published","published":"2021-02-08T21:17:58Z","modified":"2026-09-10T03:49:13.926993251Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:37.528068Z"},{"id":"CLSA-2026-1784769550","title":"TuxCare security update for marked (3 CVEs)","description":"TuxCare rebuilt marked to address 3 CVEs. Fixed in 1.2.7-tuxcare.1.","status":"published","published":"2026-08-04T14:52:47Z","modified":"2026-10-15T09:47:36.886842393Z","updated_at":"2026-11-02T15:43:46.482572Z"}]}}