Roundcube before 1.4.11 allows XSS via crafted Cascading Style Sheets (CSS) token sequences during HTML email rendering.
github.com/roundcube/roundcubemail/commit/9dc276d5f26042db02754fa1bac6fbd683c6d596
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/5QPAMYM2DQODSCQIAVNFJR2ETG7WMJOD/
lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Q752JPOHTR6H72FK3EIPJZ5O24Z7RGLM/
roundcube.net/news/2021/02/08/security-update-1.4.11