{"id":"CVE-2026-26962","state":"PUBLISHED","title":"Rack: Header injection in multipart requests","description":"Rack is a modular Ruby web server interface. From version 3.2.0 to before version 3.2.6, Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename or name instead of removing the folded line break during unfolding. As a result, applications that later reuse those parsed values in HTTP response headers may be vulnerable to downstream header injection or response splitting. This issue has been patched in version 3.2.6.","publishedAt":"2026-04-02T17:10:17.091Z","updatedAt":"2026-04-03T18:13:06.632Z","severity":{"score":4.8,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["rack rack"],"affected":[{"vendor":"rack","product":"rack","versions":[{"version":">= 3.2.0, < 3.2.6","status":"affected"}]}],"references":["https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv"],"weaknesses":["CWE-93"],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/26xxx/CVE-2026-26962.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-26962","state":"PUBLISHED","datePublished":"2026-04-02T17:10:17.091Z","dateUpdated":"2026-04-03T18:13:06.632Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-02-16T22:20:28.612Z"},"containers":{"cna":{"title":"Rack: Header injection in multipart requests","descriptions":[{"lang":"en","value":"Rack is a modular Ruby web server interface. From version 3.2.0 to before version 3.2.6, Rack::Multipart::Parser unfolds folded multipart part headers incorrectly. When a multipart header contains an obs-fold sequence, Rack preserves the embedded CRLF in parsed parameter values such as filename or name instead of removing the folded line break during unfolding. As a result, applications that later reuse those parsed values in HTTP response headers may be vulnerable to downstream header injection or response splitting. This issue has been patched in version 3.2.6."}],"affected":[{"vendor":"rack","product":"rack","versions":[{"version":">= 3.2.0, < 3.2.6","status":"affected"}]}],"references":[{"url":"https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv","name":"https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.8,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-93","lang":"en","description":"CWE-93: Improper Neutralization of CRLF Sequences ('CRLF Injection')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-02T17:10:17.091Z"},"source":{"advisory":"GHSA-rx22-g9mx-qrhv","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-02T18:31:17.511210Z","id":"CVE-2026-26962","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-03T18:13:06.632Z"}}]}}}