Bugzilla 2.x through 4.0.x before 4.0.15, 4.1.x and 4.2.x before 4.2.11, 4.3.x and 4.4.x before 4.4.6, and 4.5.x before 4.5.6 allows remote authenticated users to obtain sensitive private-comment information by leveraging a role as a flag recipient, related to Bug.pm, Flag.pm, and a mail template.