{"id":"CVE-2026-26962","summary":"Rack: Header injection in multipart requests","details":"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.","aliases":["GHSA-rx22-g9mx-qrhv"],"modified":"2026-04-06T00:44:16.470648075Z","published":"2026-04-02T17:10:17.091Z","related":["CGA-99f4-28j2-7vxm"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26962.json","cwe_ids":["CWE-93"],"cna_assigner":"GitHub_M"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/26xxx/CVE-2026-26962.json"},{"type":"ADVISORY","url":"https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-26962"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/rack/rack","events":[{"introduced":"b68251c03788ff39d4a4b25424df7360426e4afd"},{"fixed":"e1f22fdbe99afd2126b6fbf05bb12399359574b7"}],"database_specific":{"versions":[{"introduced":"3.2.0"},{"fixed":"3.2.6"}]}}],"versions":["v3.2.0","v3.2.1","v3.2.2","v3.2.3","v3.2.4","v3.2.5"],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-26962.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"}]}