{"action":"Upgrade rack to 2.2.23 or later.","affected":[{"fixed":"2.2.23","introduced":"0"},{"fixed":"3.1.21","introduced":"3.0.0.beta1"},{"fixed":"3.2.6","introduced":"3.2.0"}],"component":"rack","cve_ids":["CVE-2026-26961"],"ecosystem":"RubyGems","epss":0.00262,"exploited":false,"fixed_versions":["2.2.23","3.1.21","3.2.6"],"ghsa_id":"GHSA-vgpv-f759-9wx3","id":"tcs_01M5KENJGYNP3CC6A9P2E9HYSH","modified_at":"2026-09-10T03:51:03.337006080Z","published_at":"2026-04-02T20:30:40Z","references":["https://osv.dev/vulnerability/GHSA-vgpv-f759-9wx3","https://github.com/rack/rack/security/advisories/GHSA-vgpv-f759-9wx3","https://nvd.nist.gov/vuln/detail/CVE-2026-26961","https://github.com/rack/rack","https://github.com/rubysec/ruby-advisory-db/blob/master/gems/rack/CVE-2026-26961.yml"],"severity":{"label":"medium","score":5.3},"sources":[{"source":"osv","source_id":"GHSA-vgpv-f759-9wx3","url":"https://osv.dev/vulnerability/GHSA-vgpv-f759-9wx3"}],"summary":"Rack's greedy multipart boundary parsing can cause parser differentials and WAF bypass."}