{"cve":"CVE-2021-22902","nvd":{"published":"2021-06-11T16:15:11.360","modified":"2026-06-17T03:37:59.480","status":"Modified","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.","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-400"],"references":["https://discuss.rubyonrails.org/t/cve-2021-22902-possible-denial-of-service-vulnerability-in-action-dispatch/77866","https://hackerone.com/reports/1138654","https://discuss.rubyonrails.org/t/cve-2021-22902-possible-denial-of-service-vulnerability-in-action-dispatch/77866","https://hackerone.com/reports/1138654"],"products":["rubyonrails:rails"],"source":"nvd","synced_at":"2026-10-19T21:20:07.141963181+00:00"},"epss":{"cve":"CVE-2021-22902","score":0.02868,"percentile":0.8679,"date":"2026-10-31"},"kev":null,"osv":[{"id":"GHSA-g8ww-46x2-2p65","url":"https://osv.dev/vulnerability/GHSA-g8ww-46x2-2p65","summary":"Denial of Service in Action Dispatch","modified":"2024-02-16T08:21:28.149273Z","packages":[{"ecosystem":"RubyGems","name":"actionpack","purl":"pkg:gem/actionpack","ranges":[">=6.0.0 <6.0.3.7"],"fixed":["6.0.3.7"]},{"ecosystem":"RubyGems","name":"actionpack","purl":"pkg:gem/actionpack","ranges":[">=6.1.0 <6.1.3.2"],"fixed":["6.1.3.2"]}]}],"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."]}