The course upload preview contained an XSS risk for users uploading unsafe data.
https://moodle.org/mod/forum/discuss.php?d=451588
https://bugzilla.redhat.com/show_bug.cgi?id=2243447
http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-79455