badges/mybadges.php in Moodle 2.5.x before 2.5.5 and 2.6.x before 2.6.2 does not properly track the user to whom a badge was issued, which allows remote authenticated users to modify the visibility of an arbitrary badge via unspecified vectors.
Weaknesses in this category are related to the management of permissions, privileges, and other security features that are used to perform access control.