Roundcube Webmail before 1.6.17 and 1.7.x before 1.7.2 allows Stored Cross-Site Scripting (XSS). The issue occurs because the attachment MIME type is not properly escaped on the attachment-validation warning page.
https://roundcube.net/news/2026/07/05/security-updates-1.6.17-and-1.7.2