KB5066366: Auth Certificate export through Exchange cmdlet is no longer supported

Description of the security update for Microsoft Exchange Server Subscription Edition RTM: October 14, 2025 (KB5066366)

This security update rollup resolves vulnerabilities in Microsoft Exchange Server. To learn more about these vulnerabilities, see the following Common Vulnerabilities and Exposures (CVE)

• ​​​​​​​​​​​​​​CVE-2025-59249 - Microsoft Exchange Server Elevation of Privilege Vulnerability
• CVE-2025-53782 - Microsoft Exchange Server Elevation of Privilege Vulnerability
• CVE-2025-59248 - Microsoft Exchange Server Spoofing Vulnerability

Issues that are fixed in this update

• Auth Certificate export through Exchange cmdlet is no longer supported