Authentication Bypass by Spoofing in GitLab

An issue has been discovered in GitLab CE/EE affecting all versions before 16.9.6, all versions starting from 16.10 before 16.10.4, all versions starting from 16.11 before 16.11.1. Under certain conditions, an attacker through a crafted email address may be able to bypass domain based restrictions on an instance or a group.