mod_css_styles in Roundcube through 1.5.7 and 1.6.x through 1.6.7 insufficiently filters Cascading Style Sheets (CSS) token sequences in rendered e-mail messages, allowing a remote attacker to obtain sensitive information.
github.com/roundcube/roundcubemail/releases
github.com/roundcube/roundcubemail/releases/tag/1.5.8
github.com/roundcube/roundcubemail/releases/tag/1.6.8
roundcube.net/news/2024/08/04/security-updates-1.6.8-and-1.5.8
sonarsource.com/blog/government-emails-at-risk-critical-cross-site-scripting-vulnerability-in-roundcube-webmail/