October 13, 2020 - KB4580358 (Security-only update)
Applies to: Windows 8.1, Windows Server 2012 R2, Windows Embedded 8.1 Industry Enterprise, Windows Embedded 8.1 Industry Pro
IMPORTANT Release notes are changing! To learn about the new URL, metadata updates, and more, see What’s next for Windows release notes.
IMPORTANT Windows 8.1 and Windows Server 2012 R2 have reached the end of mainstream support and are now in extended support. Starting in July 2020, there will no longer be optional, non-security releases (known as "C" releases) for this operating system. Operating systems in extended support have only cumulative monthly security updates (known as the "B" or Update Tuesday release).
IMPORTANT Starting in July 2020, all Windows Updates will disable the RemoteFX vGPU feature because of a security vulnerability. For more information about the vulnerability, see CVE-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.”
Improvements and fixes
- "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)”
This security update includes improvements and fixes that were a part of update KB4577066 (released September 8, 2020) and addresses the following issues:
For more information about the resolved security vulnerabilities, please refer to the Security Update Guide.
- Corrects the end date for daylight savings time (DST) in 2021 for the Fiji Islands. For more information, see DST correction in Windows for the Fiji Islands: October 13, 2020.
- Security updates to Windows App Platform and Frameworks, Windows Graphics, Windows Shell, Windows Silicon Platform, Windows Cloud Infrastructure, Windows Fundamentals, Windows Authentication, Windows Virtualization, Windows Kernel, Windows Core Networking, Windows Network Security and Containers, Windows Remote Desktop, and Windows SQL components.
Known issues in this update
How to get this update
Before installing this update
We strongly recommend that you install the latest servicing stack update (SSU) for your operating system before you install the latest Rollup. SSUs improve the reliability of the update process to mitigate potential issues while installing the Rollup and applying Microsoft security fixes. For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.
If you use Windows Update, the latest SSU (KB4566425) will be offered to you automatically. To get the standalone package for the latest SSU, search for it in the Microsoft Update Catalog.
REMINDER If you are using Security-only updates, you will also need to install all previous Security-only updates and the latest cumulative update for Internet Explorer (KB4577010).
Install this update
For a list of the files that are provided in this update, download the file information for update 4580358.
Direct download links for KB4580358 MSU file from Microsoft Update Catalog:
Download KB4580358 MSU for Windows 8.1 32-bit (x86) - 34.0 MB
Download KB4580358 MSU for Windows 8.1 64-bit (x64) - 57.1 MB