A newly discovered privilege escalation vulnerability in Windows Server 2025, known as the “BadSuccessor” attack, allows attackers to compromise any user within Active Directory (AD), including those with Domain Admin privileges. This vulnerability stems from the delegated Managed Service Account (dMSA) feature, which can be exploited by creating a new dMSA linked to any user or computer account without requiring direct access to the original account. Researchers found that 91% of examined environments had users outside the Domain Admin group with the necessary permissions to execute this attack. Microsoft has been notified and is working on a patch, while organizations are advised to restrict dMSA creation to trusted administrators and enhance their security measures.