March 10, 2026—KB5078740 (OS Build 26100.32522) (original) (raw)
Applies To
Windows Server 2025, all editions
Version:
OS Build 26100.32522
This cumulative update for Windows Server 2025 (KB5078740), includes the latest security fixes and improvements, along with non-security updates from last month’s optional preview release. To learn more about differences between security updates, optional non-security preview updates, out-of-band (OOB) updates, and continuous innovation, see Windows monthly updates explained. For information on Windows update terminology, see the different types of Windows software updates.
To view the latest updates about this release, visit the Windows release health dashboard or the update history page for Windows Server 2025.
Announcements and messages
This section provides key notifications related to this release, including announcements, change logs, and end-of-support notices.
Windows Secure Boot certificate expiration
Important: Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. This might affect the ability of certain personal and business devices to boot securely if not updated in time. To avoid disruption, we recommend reviewing the guidance and taking action to update certificates in advance. For details and preparation steps, see Windows Secure Boot certificate expiration and CA updates and the Windows Server Secure playbook blog.
| Change date | Change description |
|---|---|
| June 4, 2026 | Corrected the x64 .msu update string on the Catalog tab for KB5078740 (this update) |
| March 10, 2026 | This update does not include any changes. |
Improvements
This security update contains fixes and quality improvements from KB5075899 (released February 10, 2026). The following summary outlines key issues addressed by this update. Also, included are available new features. The bold text within the brackets indicates the item or area of the change.
- [Secure Boot] With this update, Windows quality updates include additional high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. This targeting is based primarily on client device diagnostic data; due to limited data, servers are unlikely to qualify, though not explicitly excluded. Devices receive new certificates only after demonstrating sufficient successful update signals, maintaining a controlled and phased rollout.
- [System services and reliability] Improved: Windows Server 2025 now supports newer server platforms that expose more hardware error reporting features, including systems with up to 64 Machine Check Architecture (MCA) banks. This update ensures Windows parses and configures all supported error sources, so hardware errors are reported and handled as expected on modern servers such as newer AMD EPYC‑based systems.
If you've already installed previous updates, your device will download and install only the new updates included in this package.
For more information about security vulnerabilities, see the Security Update Guide and the March 2026 Security Updates.
Windows Server 2025 servicing stack update (KB5078739) - 26100.32500
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
After installing KB5070881 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.
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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File information
For a list of the files provided in this update, download the file information for cumulative update 5078740.
For a list of the files provided in the servicing stack update, download the file information for the SSU (KB5078739) - version 26100.32500.
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