{"cve":"CVE-2026-26962","nvd":{"published":"2026-04-02T18:16:26.773","modified":"2026-07-24T21:10:00.143","status":"Analyzed","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","score":6.5},"cwes":["CWE-93"],"references":["https://github.com/rack/rack/security/advisories/GHSA-rx22-g9mx-qrhv"],"products":["rack:rack"],"source":"nvd","synced_at":"2026-10-19T22:28:18.033120106+00:00"},"epss":{"cve":"CVE-2026-26962","score":0.00235,"percentile":0.1457,"date":"2026-11-01"},"kev":null,"osv":[{"id":"GHSA-rx22-g9mx-qrhv","url":"https://osv.dev/vulnerability/GHSA-rx22-g9mx-qrhv","summary":"Rack's improper unfolding of folded multipart headers preserves CRLF in parsed parameter values","modified":"2026-09-10T03:51:03.209768917Z","packages":[{"ecosystem":"RubyGems","name":"rack","purl":"pkg:gem/rack","ranges":[">=3.2.0 <3.2.6"],"fixed":["3.2.6"]}]}],"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."]}