{"id":"DEBIAN-CVE-2026-53727","details":"css_parser is a Ruby CSS parser. From 2.2.0 until 3.0.0, CssParser::Parser#read_remote_file in lib/css_parser/parser.rb, and therefore load_uri! and the @import-following branch of add_block!, issued HTTP and HTTPS requests against any host, port, and URI without a scheme allowlist, host or IP filtering, or protection against link-local, loopback, or RFC-1918 addresses. Location: redirects were followed recursively back into the same function, which also serviced file:// URIs, so a single attacker-controlled HTTP redirect could upgrade the bug from SSRF to arbitrary local file disclosure. Any consumer of css_parser that hands it attacker-influenced CSS together with a base_uri: option is exposed. This issue is fixed in version 3.0.0.","modified":"2026-09-14T17:03:19.301934970Z","published":"2026-07-17T21:17:07.837Z","upstream":["CVE-2026-53727"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2026-53727"}],"affected":[{"package":{"name":"ruby-css-parser","ecosystem":"Debian:12","purl":"pkg:deb/debian/ruby-css-parser?arch=source&distro=bookworm"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.16.0-1","1.19.0-1","1.21.1-1","1.6.0-2","1.6.0-2+deb12u1","2.0.0-1","2.1.0-1","3.0.0-1","3.1.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53727.json"}},{"package":{"name":"ruby-css-parser","ecosystem":"Debian:13","purl":"pkg:deb/debian/ruby-css-parser?arch=source&distro=trixie"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.19.0-1","1.19.0-1+deb13u1","1.21.1-1","2.0.0-1","2.1.0-1","3.0.0-1","3.1.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53727.json"}},{"package":{"name":"ruby-css-parser","ecosystem":"Debian:14","purl":"pkg:deb/debian/ruby-css-parser?arch=source&distro=forky"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.0-1"}]}],"versions":["1.19.0-1","1.21.1-1","2.0.0-1","2.1.0-1"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-53727.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N"}]}