CVE-2016-2154 (moodle)

admin/tool/monitor/lib.php in Event Monitor in Moodle 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 does not consider the moodle/course:viewhiddencourses capability, which allows remote authenticated users to discover hidden course names by subscribing to a rule.

Source: CVE-2016-2154 (moodle)