Skip to the content
The Update Bureau
Windows Server 2025 Windows Server 2025 Security update
Patch Tuesday

KB5078740

KB5078740: Cumulative update for Windows Server, version 2025, March 2026. Secure Boot targeting expands; newer server errors are handled

In short

Fixes 39 Important vulnerabilities and expands targeted delivery of new Secure Boot certificates. It also improves hardware error reporting on newer server platforms.

Does it affect you? Applies to: Devices running Windows Server 2025, x64. The Secure Boot certificate targeting change applies to eligible devices; servers are unlikely to qualify based on the available diagnostic data.

Build
26100.32522
Security
39 fixed
Restart
Required
Review notes Additional details from the official release notes (1) Read note
  • What to do When configured with the listed product and classification, WSUS automatically syncs the update; the page does not say WSUS installs it automatically.

The official sources are linked at the end of the page.

What changes

Improvements 4 changes

Catalog tab

  • The x64 update string shown on the Catalog tab is corrected.1

Secure Boot

Gradual rollout Verified in package
  • Eligible devices receive new Secure Boot certificates through a controlled, phased rollout. Servers are unlikely to qualify, though they are not explicitly excluded.2
    Windows quality updates include additional high confidence device-targeting data, based primarily on client device diagnostic data. Certificates are delivered after sufficient successful update signals.

System services and reliability

  • Newer server platforms can report and handle supported hardware errors as expected, including systems with up to 64 Machine Check Architecture banks.3
    Windows Server 2025 parses and configures all supported error sources on platforms exposing newer hardware error reporting features, including newer AMD EPYC-based systems.

Servicing stack

  • The component that installs Windows updates gets quality improvements to help devices receive and install updates.4
    Includes servicing stack update KB5078739, build 26100.32500.

Known issues

  1. Open Affects: Organizations and IT administrators

    Windows Server Update Services (WSUS) does not display error details

    After KB5070881 or later updates, Windows Server Update Services (WSUS) does not display synchronization error details. This functionality was temporarily removed to address CVE-2025-59287.5

    Workaround status No workaround yet

    Microsoft has not published a manual workaround for this issue yet. Monitor release health until a resolving update is available.

Technical details

Data sheet · Security · Downloads · Components Click to collapse or expand

Data sheet

Released
2026-03-10
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5075899, KB5078135, KB5077793, KB5073379
+21 earlier KB5072033, KB5072359, KB5068861, KB5070881, KB5070773, KB5066835, KB5068221, KB5065426, KB5063878, KB5064489, KB5062553, KB5060842, KB5058411, KB5055523, KB5053598, KB5051987, KB5050009, KB5048667, KB5046617, KB5044284, KB5043080
Replaced by
KB5082063
VersionBuildChannel
2025 26100.32522 General availability

Security

39 vulnerabilities fixed
39 important
VulnerabilitySeverityCVSS

The table lists the 0 exploited, publicly disclosed or critical vulnerabilities. See all 39 vulnerabilities →

Updated components

837 files changed since the previous update for the same versions.

Top changed componentsFiles
Networking14
Graphics and display13
Audio9
Hyper-V and virtualization8
Storage and file systems7
File Explorer and shell6
Kernel5
Secure Boot5
Security and sign-in3
Settings2
Bluetooth1
Magnifier1

Verified in package: changed files confirm Secure Boot.

Sources

Updated
Cited passages from Microsoft's official notes (5)
  1. 1. Corrected the x64 .msu update string on the Catalog tab for KB5078740 (this update) support.microsoft.com
  2. 2. 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. support.microsoft.com
  3. 3. 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. support.microsoft.com
  4. 4. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
  5. 5. 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. support.microsoft.com
Checked automatically: 7 of 8 checks passed, 5 quoted passages · compared with Microsoft's page on Sep 25, 2026
  • Quotes found in the official pages: passed
  • Numbers found in the sources: passed
  • Vulnerabilities from the dossier only: passed
  • Links to allowed domains only: passed
  • Every official change covered: passed
  • Readable plain text: passed
  • Changes confirmed by the file list: passed
  • Sources agree: not passed

A second AI read the text against the sources: correctness 4/5, clarity 4/5, completeness 5/5. How we work

Published by The Update Bureau. Written with AI from Microsoft's own documents, checked by rules and a second AI. How we work · Report a mistake