{"id":"CVE-2026-35540","aliases":["DEBIAN-CVE-2026-35540","EUVD-2026-18583","GHSA-vxg2-hhgr-37fx","UBUNTU-CVE-2026-35540"],"status":"published","title":"Roundcube Webmail: Insufficient CSS sanitization in HTML e-mail messages","description":"An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. 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hosts.","severity":{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00401,"percentile":0.34805,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-669","CWE-918"],"published":"2026-04-03T03:47:51Z","modified":"2026-10-28T02:31:03Z","fixes":[{"ecosystem":"Packagist","package":"roundcube/roundcubemail","fixed_in":["1.7-rc5"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:12","package":"roundcube","fixed_in":["1.6.5+dfsg-1+deb12u8"],"sources":["osv"]},{"ecosystem":"Debian:13","package":"roundcube","fixed_in":["1.6.15+dfsg-0+deb13u1"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"roundcube","fixed_in":["1.6.14+dfsg-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Packagist","package":"roundcube/roundcubemail","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.7-beta"},{"fixed":"1.7-rc5"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.5+dfsg-1+deb12u8"}]}],"versions":["1.6.1+dfsg-1","1.6.2+dfsg-1","1.6.3+dfsg-1","1.6.3+dfsg-1~deb12u1","1.6.3+dfsg-2","1.6.4+dfsg-1","1.6.4+dfsg-1~deb12u1","1.6.5+dfsg-1","1.6.5+dfsg-1+deb12u2","1.6.5+dfsg-1+deb12u3","1.6.5+dfsg-1+deb12u4","1.6.5+dfsg-1+deb12u5","1.6.5+dfsg-1+deb12u6","1.6.5+dfsg-1+deb12u7","1.6.5+dfsg-1~deb12u1"]},{"source":"osv","ecosystem":"Debian:13","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.15+dfsg-0+deb13u1"}]}],"versions":["1.6.11+dfsg-1","1.6.12+dfsg-0+deb13u1","1.6.12+dfsg-1","1.6.13+dfsg-0+deb13u1","1.6.13+dfsg-1","1.6.14+dfsg-1"]},{"source":"osv","ecosystem":"Debian:14","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.6.14+dfsg-1"}]}],"versions":["1.6.11+dfsg-1","1.6.12+dfsg-1","1.6.13+dfsg-1"]},{"source":"osv","ecosystem":"Packagist","package":"roundcube/roundcubemail","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.7-beta"},{"fixed":"1.7-rc5"}]}],"versions":["1.7-beta","1.7-beta2","1.7-rc","1.7-rc2","1.7-rc3","1.7-rc4"]},{"source":"osv","ecosystem":"Ubuntu:Pro:16.04:LTS","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.1+dfsg.1-2","1.1.2+dfsg.1-5","1.1.3+dfsg.1-1","1.1.4+dfsg.1-1","1.2~beta+dfsg.1-0ubuntu1","1.2~beta+dfsg.1-0ubuntu1+esm1","1.2~beta+dfsg.1-0ubuntu1+esm2","1.2~beta+dfsg.1-0ubuntu1+esm3","1.2~beta+dfsg.1-0ubuntu1+esm4","1.2~beta+dfsg.1-0ubuntu1+esm5","1.2~beta+dfsg.1-0ubuntu1+esm6","1.2~beta+dfsg.1-0ubuntu1+esm7","1.2~beta+dfsg.1-0ubuntu1+esm8"]},{"source":"osv","ecosystem":"Ubuntu:Pro:18.04:LTS","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.0+dfsg.1-1","1.3.1+dfsg.1-1","1.3.3+dfsg.1-1","1.3.3+dfsg.1-2","1.3.6+dfsg.1-1","1.3.6+dfsg.1-1ubuntu0.1~esm1","1.3.6+dfsg.1-1ubuntu0.1~esm2","1.3.6+dfsg.1-1ubuntu0.1~esm3","1.3.6+dfsg.1-1ubuntu0.1~esm4","1.3.6+dfsg.1-1ubuntu0.1~esm5","1.3.6+dfsg.1-1ubuntu0.1~esm6","1.3.6+dfsg.1-1ubuntu0.1~esm7","1.3.6+dfsg.1-1ubuntu0.1~esm8"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.3.8+dfsg.1-2","1.3.10+dfsg.1-1","1.4.1+dfsg.1-2","1.4.2+dfsg.1-1","1.4.2+dfsg.1-2","1.4.3+dfsg.1-1","1.4.3+dfsg.1-1ubuntu0.1~esm1","1.4.3+dfsg.1-1ubuntu0.1~esm2","1.4.3+dfsg.1-1ubuntu0.1~esm3","1.4.3+dfsg.1-1ubuntu0.1~esm4","1.4.3+dfsg.1-1ubuntu0.1~esm5","1.4.3+dfsg.1-1ubuntu0.1~esm6","1.4.3+dfsg.1-1ubuntu0.1~esm7","1.4.3+dfsg.1-1ubuntu0.1~esm8"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.4.11+dfsg.1-4","1.5.0+dfsg.1-2","1.5.0+dfsg.1-2ubuntu0.1~esm1","1.5.0+dfsg.1-2ubuntu0.1~esm2","1.5.0+dfsg.1-2ubuntu0.1~esm3","1.5.0+dfsg.1-2ubuntu0.1~esm4","1.5.0+dfsg.1-2ubuntu0.1~esm5","1.5.0+dfsg.1-2ubuntu0.1~esm6"]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.2+dfsg-1","1.6.4+dfsg-1","1.6.5+dfsg-1","1.6.6+dfsg-1","1.6.6+dfsg-2","1.6.6+dfsg-2ubuntu0.1","1.6.6+dfsg-2ubuntu0.1+esm1","1.6.6+dfsg-2ubuntu0.1+esm2","1.6.6+dfsg-2ubuntu0.1+esm3"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.10+dfsg-1","1.6.10+dfsg-2","1.6.11+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.11+dfsg-1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:26.04:LTS","package":"roundcube","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.11+dfsg-1","1.6.11+dfsg-1ubuntu0.26.04.1~esm1"]}],"products":[{"vendor":"bulwarkm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Advisory","web","report"]},{"url":"https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5","tags":["Release Notes","web","report"]},{"url":"https://github.com/roundcube/roundcubemail/commit/579b68eff90650a5c782e153debd66c765648942","tags":["Patch","fix","web","report"]},{"url":"https://github.com/roundcube/roundcubemail/releases/tag/1.6.14","tags":["Release Notes","web","report"]},{"url":"https://github.com/roundcube/roundcubemail/commit/27ec6cc9cb25e1ef8b4d4ef39ce76d619caa6870","tags":["Patch","fix","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35540","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-vxg2-hhgr-37fx"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35540.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-35540","tags":["advisory"]},{"url":"https://github.com/roundcube/roundcubemail","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-35540","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-35540","tags":["report"]},{"url":"https://i0.rs/blog/turning-a-roundcube-link-tag-into-a-zero-day-ssrf-and-data-exfiltration/","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-35540","description":"An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts.","status":"published","published":"2026-04-03T03:47:51.456Z","modified":"2026-04-03T12:52:38.24Z","cvss":[{"version":"3.1","score":5.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-669"],"updated_at":"2026-11-02T14:20:05.15083Z"}],"euvd":[{"id":"EUVD-2026-18583","description":"An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. 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Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to SSRF or Information Disclosure, e.g., if stylesheet links point to local network hosts.","status":"published","published":"2026-04-03T05:16:22.1Z","modified":"2026-10-01T03:03:22.351488276Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N","level":"medium"}],"updated_at":"2026-11-02T15:45:54.587575Z"},{"id":"GHSA-vxg2-hhgr-37fx","title":"Roundcube Webmail: Insufficient CSS sanitization in HTML e-mail messages","description":"An issue was discovered in Roundcube Webmail 1.6.0 before 1.6.14. 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