October 24, 2025—KB5070893 (OS Build 26100.6905) Security Update for Windows Server Update Services
Applies To
Release Date:
10/24/2025
Version:
OS Build 26100.6905
Windows Secure Boot certificate expiration
Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. Microsoft has been updating these certificates on consumer and non-managed business devices for the past months. Devices that haven’t received the newer certificates will continue to start and operate normally, and standard Windows updates will continue to install. We will continue to install the newer certificates via Windows updates in the coming months.
You can check your PC status on the Windows Security app. If you are an IT administrator, follow the guidance on the Secure Boot Playbook for Windows clients and Windows Server.​​​​​​​
This update applies to Windows Server 2025 Datacenter & Standard machines connected to Azure Arc. To learn more about Windows update terminology, see types of Windows updates and the monthly quality update types. For an overview, see the update history page for Windows Server 2025. Â
Stay informed! Follow @WindowsUpdate for the latest updates from the Windows Release Health Dashboard.
Improvements and fixes
This security update includes quality improvements. The following summary outlines key issues addressed by this update.
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[Windows Server Update Services (WSUS)] Fixed: This update addresses a remote code execution (RCE) vulnerability that was identified in WSUS reporting web services. For more information about the security fix, see CVE-2025-59287.
This is a standalone update that requires a reboot only for Servers that have WSUS enabled. This update will not reset the previous baseline.​​​​​​​
If you've already installed previous updates, your device will download and install only the new updates included in this package.
Known issues in this update
After installing KB5070893Â or later updates, Windows Server Update Services (WSUS) does not display synchronization error details within its error reporting. This functionality is temporarily removed to address the Remote Code Execution Vulnerability, CVE-2025-59287.Â
Symptoms
The out-of-band update for Windows Server 2025Â (KB5070881)Â was briefly offered to all Windows Server 2025 machines, regardless of Hotpatch enrollment.Â
Machines that installed KB5070881 will temporarily stop receiving Hotpatch updates and will instead receive security updates that require a restart.
Workaround
​​​​​​​This issue is addressed in KB5073379.
How to get this update
Before you install this update
Microsoft combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.Â
Install this update
To install this update, use one of the following Windows and Microsoft release channels.
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This update downloads and installs automatically from Windows update and Microsoft Update. |
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See the Windows Update option. |
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his update will automatically sync with Windows Server Update Services (WSUS) if you configure Products and Classifications as follows: Product: Microsoft Server operating system-24H2 Classification: Security Updates |
If you want to remove the LCU
To remove the LCU after installing the combined SSU and LCU package, use the DISM/Remove-Package command line option with the LCU package name as the argument. You can find the package name by using this command: DISM /online /get-packages.
Running Windows Update Standalone Installer (wusa.exe) with the /uninstall switch on the combined package will not work because the combined package contains the SSU. You cannot remove the SSU from the system after installation.
​​​​​​​File information
For a list of the files that are in this update, download the file information for cumulative update 5070893.
For a list of the files that are in the servicing stack update, download the file information for the SSU (KB5067360) - version 26100.6893.
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