CVE-2026-114722

Summary

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”.

Impact & exploitability

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected products we track (1)

Recommendation

Apply the vendor fix in your normal patch cycle. Open any affected product above for its exact safe version.

Official patch: https://github.com/roundcube/roundcubemail/commit/95b81ae12e2819a9b7e8636b5859b6244cda383e ↗

Additional information

• NVD record
• https://github.com/roundcube/roundcubemail/commit/95b81ae12e2819a9b7e8636b5859b6244cda383ePatch
• https://github.com/roundcube/roundcubemail/commit/ff9cf4a9bf3b7c66db9afe43fe5f1cc73b47ed35Patch
• https://bugs.debian.org/1151279Advisory
• https://github.com/roundcube/roundcubemail/releases/tag/1.6.20
• https://github.com/roundcube/roundcubemail/releases/tag/1.7.5
• https://roundcube.net/news/2026/10/19/security-updates-1.6.20-and-1.7.5