{"id":"CVE-2021-22902","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-22902","generatedAt":"2026-10-27T23:45:18.276Z","title":"The actionpack ruby gem (a framework for handling and responding to web requests in Rails) before 6.0.3.7, 6.1.3.2 suffers from a possible denial of service vulnerability in the Mime type parser of Action Dispatch.","description":"The actionpack ruby gem (a framework for handling and responding to web requests in Rails) before 6.0.3.7, 6.1.3.2 suffers from a possible denial of service vulnerability in the Mime type parser of Action Dispatch. Carefully crafted Accept headers can cause the mime type parser in Action Dispatch to do catastrophic backtracking in the regular expression engine.","published":"2021-06-11T16:15:11.000Z","lastModified":"2026-06-17T03:37:59.000Z","status":"Modified","sourceIdentifier":"support@hackerone.com","cvss":{"version":"3.1","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"},"cwe":["CWE-400"],"affected":["rubyonrails/rails"],"epss":{"score":0.02868,"percentile":0.86696,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.87%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://discuss.rubyonrails.org/t/cve-2021-22902-possible-denial-of-service-vulnerability-in-action-dispatch/77866","tags":["Exploit","Mitigation","Patch","Vendor Advisory"],"source":"support@hackerone.com"},{"url":"https://hackerone.com/reports/1138654","tags":["Permissions Required","Third Party Advisory"],"source":"support@hackerone.com"},{"url":"https://discuss.rubyonrails.org/t/cve-2021-22902-possible-denial-of-service-vulnerability-in-action-dispatch/77866","tags":["Exploit","Mitigation","Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://hackerone.com/reports/1138654","tags":["Permissions Required","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-22902","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}