Bugzilla 2.23.3 through 2.22.7, 3.0.x through 3.3.x, 3.4.x before 3.4.12, 3.5.x, 3.6.x before 3.6.6, 3.7.x, 4.0.x before 4.0.2, and 4.1.x before 4.1.3 allows remote attackers to determine the existence of private group names via a crafted parameter during (1) bug creation or (2) bug editing.