LegacyHive: Windows ProfSvc enabling cross-user registry Hive Loading

LegacyHive is a Windows local privilege-escalation zero-day that abuses the User Profile Service’s registry hive-loading logic to redirect or expose another user’s hive, including administrative profiles. By combining registry manipulation, symbolic links, and a race condition, it can enable SYSTEM-level access, persistence, and follow-on code execution on affected systems.