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 1.3.12 and 1.4.x before 1.4.5. include/rcmail_output_html.php allows XSS via the username template object.
An issue was discovered in Roundcube Webmail before 1.3.12 and 1.4.x before 1.4.5. There is XSS via a malicious XML attachment because text/xml is among the allowed types for a preview.
An issue was discovered in Roundcube Webmail before 1.4.4. There is a cross-site scripting (XSS) vulnerability in rcube_washtml.php because JavaScript code can occur in the CDATA of an HTML message.
An issue was discovered in Roundcube Webmail before 1.4.4. A CSRF attack can cause an authenticated user to be logged out because POST was not considered.
In Roundcube Webmail before 1.3.10, an attacker in possession of S/MIME or PGP encrypted emails can wrap them as sub-parts within a crafted multipart email. The encrypted part(s) can further be hidden using HTML/CSS or ASCII newline characters. This modified multipart email can be re-sent by the attacker to the intended receiver. If the receiver replies to this (benign looking) email, they unknowingly leak the plaintext of the encrypted message part(s) back to the attacker.