{"id":"DEBIAN-CVE-2026-125109","details":"Rack is a modular Ruby web server interface. From 3.0 until 3.1.23 and 3.2.8, Rack::Request#host_with_port, #base_url, and #url can return an attacker-controlled invalid authority from Host, X-Forwarded-Host, or Forwarded: host= verbatim. Applications without an independent host allowlist that use these methods for absolute URLs, redirects, or origin-dependent checks can emit attacker-chosen delimiters, enabling redirect manipulation, string-based allowlist bypass, or unescaped markup reflection. Rails overrides these methods and is not expected to be affected. This issue is fixed in versions 3.1.23 and 3.2.8.","modified":"2026-11-10T13:00:06.294709366Z","published":"2026-11-09T22:18:42.127Z","upstream":["CVE-2026-125109"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-125109"}],"affected":[{"package":{"name":"ruby-rack","ecosystem":"Debian:12","purl":"pkg:deb/debian/ruby-rack?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.2.13-1~deb12u1","2.2.20-0+deb12u1","2.2.22-0+deb12u1","2.2.22-0+deb12u2","2.2.6.4-1","2.2.6.4-1+deb12u1","2.2.7-1","2.2.7-1.1","3.0.0-1","3.0.8-1","3.0.8-2","3.0.8-3","3.0.8-4","3.1.12-1","3.1.12-2~exp1","3.1.16-0.1","3.1.18-1","3.1.18-1~deb13u1","3.1.9-1~exp1","3.1.9-2","3.2.4-1","3.2.5-1","3.2.5-2","3.2.6-1","3.2.6-2","3.2.6-3","3.2.7-1","3.2.8-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-125109.json"}},{"package":{"name":"ruby-rack","ecosystem":"Debian:13","purl":"pkg:deb/debian/ruby-rack?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.1.16-0.1","3.1.18-1","3.1.18-1~deb13u1","3.1.20-0+deb13u1","3.1.20-0+deb13u2","3.2.4-1","3.2.5-1","3.2.5-2","3.2.6-1","3.2.6-2","3.2.6-3","3.2.7-1","3.2.8-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-125109.json"}},{"package":{"name":"ruby-rack","ecosystem":"Debian:14","purl":"pkg:deb/debian/ruby-rack?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.2.8-1"}]}],"versions":["3.1.16-0.1","3.1.18-1","3.1.18-1~deb13u1","3.2.4-1","3.2.5-1","3.2.5-2","3.2.6-1","3.2.6-2","3.2.6-3","3.2.7-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-125109.json"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N"}]}