KB5063709: This update contains miscellaneous security improvements to internal Windows OS functionality.

August 12, 2025—KB5063709 (OS Builds 19044.6216 and 19045.6216)

Summary
This security update includes fixes and improvements that are a part of the following updates:

• July 8, 2025—KB5062554 (OS Builds 19044.6093 and 19045.6093)
• July 22, 2025—KB5062649 (OS Build 19045.6157) Preview

The following is a summary of the key issues that this update addresses when you install this update. If there are new features, it lists them as well. The bold text within the brackets indicates the item or area of the change we are documenting.

• This build includes all the improvements from the supported Windows 10, version 21H2 editions.
• [Internal Windows OS] This update contains miscellaneous security improvements to internal Windows OS functionality. No specific issues are documented for this release