cve 2026 54121

This tag page tracks CVE 2026 54121, a high-severity privilege-escalation vulnerability in Microsoft Active Directory Certificate Services (AD CS). The flaw can allow an authenticated attacker to gain additional privileges remotely, and Microsoft describes it as an improper-authorization weakness (CWE-285) that can be exploited over a network without user interaction. Microsoft addressed the vulnerability in its July 14, 2026 security updates. Coverage focuses on the reported CVSS 3.1 score of 8.8 and the priority of patching affected certificate authority servers. Windows administrators and enterprise IT teams can use this page to follow guidance related to the security update and AD CS remediation.