KB5063221: This security update rollup resolves vulnerabilities in Microsoft Exchange Server

Description of the security update for Microsoft Exchange Server 2016: August 12, 2025 (KB5063223)

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-2025-25005 - Microsoft Exchange Server Tampering Vulnerability
• CVE-2025-25006 - Microsoft Exchange Server Spoofing Vulnerability
• CVE-2025-25007 - Microsoft Exchange Server Tampering Vulnerability
• CVE-2025-33051 - Microsoft Exchange Server Information Disclosure Vulnerability

Issues that are fixed in this update

• Exchange Server fails to export eDiscovery search results to a discovery mailbox
• Application pools stop responding and performance is affected after MSIPC is enabled
• Incorrect ACE is modified through public folder management in Outlook

Exchange Server Health Checker
To verify that that the installation is successful, and check whether any additional actions are required, run the Exchange Server Exchange Server Health Checker.