GHSA-C3VX-V4X8-X894 Moodle does not check for the moodle/course:viewhiddencourses capability

enrol/index.php in Moodle 2.6.x before 2.6.3 does not check for the moodle/course:viewhiddencourses capability before listing hidden courses, which allows remote attackers to obtain sensitive name and summary information about these courses by leveraging the guest role and visiting a crafted URL...