CVE-2026-35544

An issue was discovered in Roundcube Webmail before 1.5.14 and 1.6.14. Insufficient Cascading Style Sheets (CSS) sanitization in HTML e-mail messages may lead to a fixed-position mitigation bypass via the use of !important.

Score

CVSS 3.1 5.3 Medium

Status

Analyzed - cve@mitre.org

Published

2026-04-03

Last modified

2026-04-03

Weaknesses

CWE-669

Affected products

• Webmail (Roundcube)

References

• https://github.com/roundcube/roundcubemail/commit/099009b9c8e1d3c636fb9a5af72f7c2596018662
• https://github.com/roundcube/roundcubemail/commit/226811a1c974271dbedca72672923abaff8191c0
• https://github.com/roundcube/roundcubemail/commit/57dec0c127b98e0c8e3b9c26c80049b9c4bcaea7
• https://github.com/roundcube/roundcubemail/releases/tag/1.5.14
• https://github.com/roundcube/roundcubemail/releases/tag/1.6.14
• https://github.com/roundcube/roundcubemail/releases/tag/1.7-rc5
• https://roundcube.net/news/2026/03/18/security-updates-1.7-rc5-1.6.14-1.5.14