In Roundcube Webmail before 1.6.18 and 1.7.x before 1.7.3, improper rule name quoting could lead to managesieve_disabled_actions setting bypass via a crafted rule name in a Sieve script. This issue only affects Roundcube instances using the managesieve plugin.
https://roundcube.net/news/2026/08/09/security-updates-1.6.18-and-1.7.3
https://github.com/roundcube/roundcubemail/releases/tag/1.7.3
https://github.com/roundcube/roundcubemail/releases/tag/1.6.18