September 10, 2019—KB4516068 (OS Build 15063.2045)

**IMPORTANT:**Windows 10 Enterprise and Windows 10 Education editions will reach end of service on October 8, 2019. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10_._

**Reminder:**March 12 and April 9 were the last two Delta updates for Windows 10, version 1703. Security and quality updates will continue to be available via the express and full cumulative update packages. For more information on this change please visit our blog.

Windows 10, version 1703, reached end of service on October 8, 2018_. Devices running Windows 10 Home, Pro, Pro for Workstation, and IoT Core editions will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10._

Windows 10 Mobile, version 1703, reached end of service on June 11, 2019. Devices running Windows 10 Mobile and Windows 10 Mobile Enterprise will no longer receive monthly security and quality updates that contain protection from the latest security threats. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10.

For more information about the various types of Windows updates, such as critical, security, driver, service packs, and so on, please see the following article.

Highlights

• Updates to improve security when using Internet Explorer and input devices such as a mouse, keyboard, or stylus.
• Updates for verifying user names and passwords.
• Updates for storing and managing files.

Improvements and fixes

This security update includes quality improvements. Key changes include:

• Provides protections against a new subclass of speculative execution side-channel vulnerabilities, known as Microarchitectural Data Sampling, for 32-Bit (x86) versions of Windows (CVE-2019-11091, CVE-2018-12126, CVE-2018-12127, CVE-2018-12130). Use the registry settings as described in the Windows Client article_. _(These registry settings are enabled by default for Windows Client OS editions.)
• Security updates to Microsoft Scripting Engine, Internet Explorer, Windows App Platform and Frameworks, Windows Input and Composition, Windows Media, Windows Fundamentals, Windows Authentication, Windows Datacenter Networking, Windows Storage and Filesystems, the Microsoft JET Database Engine, Windows Kernel, Windows Virtualization, and Windows Server
  If you installed earlier updates, only the new fixes contained in this package will be downloaded and installed on your device.For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.

Windows Update ImprovementsMicrosoft has released an update directly to the Windows Update client to improve reliability. Any device running Windows 10 configured to receive updates automatically from Windows Update, including Enterprise and Pro editions, will be offered the latest Windows 10 feature update based on device compatibility and Windows Update for Business deferral policy. This doesn’t apply to long-term servicing editions.

Known issues in this update

• Perform the operation from a process that has administrator privilege.
• Perform the operation from a node that doesn’t have CSV ownership.
  Microsoft is working on a resolution and will provide an update in an upcoming release.

How to get this update