October 13, 2020—KB4580370 (OS Build 15063.2525)

NEW
IMPORTANTRelease notes are changing! To learn about the new URL, metadata updates, and more, see What’s next for Windows release notes.

Current status of Windows 10, version 1703Windows 10, version 1703 has reached end of service for all editions. To continue receiving security and quality updates, Microsoft recommends updating to the latest version of Windows 10_._Surface Hub devices remain in support. Starting on November 12, 2019, updates for Windows 10, version 1703 will be available only for Surface Hub devices. Update information and Surface Hub known issues will be listed on this page.For information about servicing timelines, see the Windows lifecycle fact sheet.

IMPORTANTStarting in July 2020, all Windows Updates will disable the RemoteFX vGPU feature because of a security vulnerability. For more information about the vulnerability, seeCVE-2020-1036 and KB4570006. After you install this update, attempts to start virtual machines (VM) that have RemoteFX vGPU enabled will fail, and messages such as the following will appear:If you re-enable RemoteFX vGPU, a message similar to the following will appear:

• “The virtual machine cannot be started because all the RemoteFX-capable GPUs are disabled in Hyper-V Manager.”
• “The virtual machine cannot be started because the server has insufficient GPU resources.”
• "We no longer support the RemoteFX 3D video adapter. If you are still using this adapter, you may become vulnerable to security risk. Learn more (https://go.microsoft.com/fwlink/?linkid=2131976)”

Highlights

• Updates 2021 time zone information for Fiji.
• Updates to improve security when using Microsoft Office products.
• Updates for verifying usernames and passwords.
• Updates to improve security when Windows performs basic operations.
• Updates for storing and managing files.

Improvements and fixes

This security update includes quality improvements. Key changes include:

• Updates 2021 time zone information for Fiji.
• Addresses an issue with a possible elevation of privilege in win32k.
• Allows administrators to disable JScript in specific security zones.
• Addresses an issue with the Group Policy service that might recursively delete critical files in alphabetic order from %systemroot%\system32. This issue occurs when a policy has been configured to delete cached profiles. These file deletions might cause stop error “0x5A (CRITICAL_SERVICE_FAILED)” boot failures.
• Addresses an issue with creating null ports using the user interface.
• Security updates to Windows App Platform and Frameworks, Microsoft Graphics Component, Windows Media, Windows Shell, Windows Cloud Infrastructure, Windows Fundamentals, Windows Authentication, Windows Virtualization, Windows Kernel, and Windows Storage and Filesystems.
  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

• An improperly formatted catalog file is identified during validation by Windows. Starting with this release, Windows will require the validity of DER encoded PKCS#7 content in catalog files. Catalogs files must be signed per section 11.6 of describing DER-encoding for SET OF members in X.690.
• A driver catalog file extension is not one of supported extensions.
  If this happens you should contact the driver vendor or device manufacturer (OEM) and ask them for an updated driver to correct the issue.

How to get this update