CVE-2026-114722
mediumRoundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a CSS scoping bypass in HTML messages.
Vendor / product: Roundcube — webmail
Roundcube Webmail before 1.6.20 and 1.7.x before 1.7.5 is affected by a CSS scoping bypass in HTML messages. rcube_utils::mod_css_styles() did not treat an at-rule prologue such as @layer a; as a selector boundary, and did not handle selectors beginning with ::, so selectors following an at-rule were left unscoped and applied to the whole Roundcube interface instead of being confined to the message body. This allows an HTML message to restyle application chrome for UI redressing and spoofing. Upstream fixed this in the commit “Fix CSS scoping bypass in HTML messages using at-rules”.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Affected products
Weakness classification (CWE)
Source: NVD / CISA. “NVD-CWE-Other” and “NVD-CWE-noinfo” mean NVD could not assign a specific weakness.
Mitigation & advisories
References
- https://bugs.debian.org/1151279 cve@mitre.org
- https://github.com/roundcube/roundcubemail/commit/95b81ae12e2819a9b7e8636b5859b6244cda383e cve@mitre.org
- https://github.com/roundcube/roundcubemail/commit/ff9cf4a9bf3b7c66db9afe43fe5f1cc73b47ed35 cve@mitre.org
- https://github.com/roundcube/roundcubemail/releases/tag/1.6.20 cve@mitre.org
- https://github.com/roundcube/roundcubemail/releases/tag/1.7.5 cve@mitre.org
- https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5 cve@mitre.org