Multiple cross-site scripting (XSS) vulnerabilities in Moodle through 2.2.11, 2.3.x before 2.3.9, 2.4.x before 2.4.6, and 2.5.x before 2.5.2 allow remote attackers to inject arbitrary web script or HTML via a crafted blog link within an RSS feed.
https://moodle.org/mod/forum/discuss.php?d=238399
http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-41623