Roundcube before 1.4.13 and 1.5.x before 1.5.2 allows XSS via an HTML e-mail message with crafted Cascading Style Sheets (CSS) token sequences.
https://www.debian.org/security/2022/dsa-5037
https://roundcube.net/news/2021/12/30/update-1.5.2-released
https://roundcube.net/news/2021/12/30/security-update-1.4.13-released
https://lists.debian.org/debian-lts-announce/2022/01/msg00005.html
https://github.com/roundcube/roundcubemail/commit/b2400a4b592e3094b6c84e6000d512f99ae0eed8
https://github.com/roundcube/roundcubemail/commit/8894fddd59b770399eed4ef8d4da5773913b5bf0