The offer_account_by_email function in User.pm in the WebService for Bugzilla before 3.0.2, and 3.1.x before 3.1.2, does not check the value of the createemailregexp parameter, which allows remote attackers to bypass intended restrictions on account creation.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.008
EPSS Ranking 73.4%