Roundcube Webmail before 1.5.10 and 1.6.x before 1.6.11 allows remote code execution by authenticated users because the _from parameter in a URL is not validated in program/actions/settings/upload.php, leading to PHP Object Deserialization.
Cross-Site Scripting (XSS) vulnerability in Roundcube Webmail 1.6.9 allows remote authenticated users to upload a malicious file as an email attachment, leading to the triggering of the XSS by visiting the SENT session.