Roundcube before 1.3.17 and 1.4.x before 1.4.12 is prone to XSS in handling an attachment's filename extension when displaying a MIME type warning message.

Roundcube Webmail before 1.3.15 and 1.4.8 allows stored XSS in HTML messages during message display via a crafted SVG document. This issue has been fixed in 1.4.8 and 1.3.15.

An issue was discovered in Roundcube Webmail before 1.2.11, 1.3.x before 1.3.14, and 1.4.x before 1.4.7. It allows XSS via a crafted HTML e-mail message, as demonstrated by a JavaScript payload in the xmlns (aka XML namespace) attribute of a HEAD element when an SVG element exists.

An issue was discovered in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5. include/rcmailoutputhtml.php allows XSS via the username template object.

Roundcube Webmail before 1.4.4 allows attackers to include local files and execute code via directory traversal in a plugin name to rcubepluginapi.php.