April 8, 2025—KB5055527 (OS Build 25398.1551)
Applies To
Windows Server, version 23H2Release Date:
4/8/2025
Version:
OS Build 25398.1551
For information about Windows update terminology, see types of Windows updates and the monthly quality update types. To find an overview of Windows Server, version 23H2, see its update history page.
Improvements
This security update includes quality improvements. The following summary outlines key issues addressed by the KB update after you install it. Also, included are available new features. The bold text within the brackets indicates the item or area of the change.
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[Daylight Saving Time (DST)] Update for the Aysen region in Chile to support the government DST change order in 2025. For more info about DST changes, see the Daylight Saving Time & Time Zone Blog.
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[OS Security] After installing this update or a later Windows update, a new %systemdrive%\inetpub folder will be created on your device. This folder should not be deleted regardless of whether Internet Information Services (IIS) is enabled on the target device. This behavior is part of changes that increase protection and does not require any action from IT admins and end users. For more information, see CVE-2025-21204.
For more information about security vulnerabilities, see the Security Update Guide and the April 2025 Security Updates.
Windows Server, version 23H2 servicing stack update (KB5053599) - 25398.1480
This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates. To learn more about SSUs, see Simplifying on-premises deployment of servicing stack updates.
Known issues in this update
Devices that have certain Citrix components installed might be unable to complete installation of the January 2025 Windows security update. This issue was observed on devices with Citrix Session Recording Agent (SRA) version 2411. The 2411 version of this application was released in December 2024. Affected devices might initially download and apply the January 2025 Windows security update correctly, such as via the Windows Update page in Settings. However, when restarting the device to complete the update installation, an error message with text similar to “Something didn’t go as planned. No need to worry – undoing changes” appears. The device will then revert to the Windows updates previously present on the device. This issue likely affects a limited number of organizations as version 2411 of the SRA application is a new version. Home users are not expected to be affected by this issue.
Citrix has documented this issue, including a workaround, which can be performed prior to installing the January 2025 Windows security update. For details, see Citrix’s documentation.
Microsoft is working with Citrix to address this issue and will update this documentation once a resolution is available.
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.
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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This update downloads and installs automatically from Windows Update for Business in accordance with configured policies. |
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To get the standalone package for this update, go to the Microsoft Update Catalog. |
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This update automatically syncs with Windows Server Update Services (WSUS) if you configure Products and Classifications as follows: Product: Microsoft Server operating system-21H2 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 provided in this update, download the file information for cumulative update 5055527.
For a list of the files that are provided in the servicing stack update, download the file information for the SSU (KB5053599) - version 25398.1480.
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