CVE-2025-26684: Microsoft Defender Elevation of Privilege Vulnerability

How can I verify that the update is installed?

Customers wanting to ensure the client has been updated can run the MDE Client Analyzer on the device. When running the analyzer on a Windows device that does not have the security update, the analyzer will present a warning (ID 121035) indicating missing patch and directing to relevant online article. Additionally, if the update is installed, but the Anti-Spoofing capability is not in a stable state, the analyzer will present warning (ID 121036) indicating an issue and providing additional online guidance or callout to reach out to Microsoft support if issue persists.