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Windows Server 2019 Windows Server 2019 Security update
Patch Tuesday

KB5078752

KB5078752: Cumulative update for Windows Server, version 2019, March 2026. Secure Boot certificate targeting expands; File History backs up more files

In short

The update fixes 38 Important-severity vulnerabilities and expands phased Secure Boot certificate targeting. File History can now back up files with certain Chinese and Private Use Area characters.

Does it affect you? Applies to: Devices running Windows Server 2019. Servers are unlikely to qualify for automatic Secure Boot certificate updates because the targeting relies primarily on client device diagnostic data, but servers are not explicitly excluded.

Build
17763.8511
Security
38 fixed
Restart
Required

Microsoft publishes separate notes for this KB for Windows 10.

What changes

Improvements 3 changes

File History

  • File History can back up new files with names containing certain Chinese and Private Use Area characters.1
    Applies to File History in Control Panel when backing up files.

Secure Boot

Gradual rollout Verified in package

For: Devices eligible for automatic Secure Boot certificate updates

  • More eligible devices can be targeted to receive new Secure Boot certificates automatically, through a controlled phased rollout.2
    Windows quality updates include additional high confidence device targeting data. Targeting is based primarily on client device diagnostic data; servers are unlikely to qualify, though not explicitly excluded. Devices receive certificates after sufficient successful update signals.

Servicing stack

  • The update checks whether a device is hosted on Azure using an updated certificate chain.3
    The bundled servicing stack update, KB5075903, includes enhanced logic to verify Azure hosting and uses an updated certificate chain for validation.

New feature 1 change

Windows System Image Manager

For: Windows System Image Manager users

  • A warning dialog helps you confirm that a selected catalog file comes from a trusted source.4

Known issues

  1. Resolved Affects: Organizations and IT administrators Resolved by KB5082123

    Japanese characters fail to render correctly in PowerShell

    On Japanese-language installations of Windows Server 2019, Japanese characters might appear garbled or as question marks in the PowerShell console after updates released on or after January 13, 2026. KB5082123 resolves this issue.5

    Resolution Fixed in KB5082123

    Install KB5082123 (or a later cumulative update) on affected devices. No manual workaround is required after updating.

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
KB5075904, KB5078131, KB5077795, KB5073723
+16 earlier KB5074975, KB5071544, KB5068791, KB5070883, KB5066586, KB5065428, KB5066187, KB5063877, KB5062557, KB5060531, KB5061978, KB5058392, KB5059091, KB5058922, KB5050008, KB5037425
Replaced by
KB5082123
VersionBuildChannel
2019 17763.8511 General availability

Security

38 vulnerabilities fixed
38 important
VulnerabilitySeverityCVSS

The table lists the 0 exploited, publicly disclosed or critical vulnerabilities. See all 38 vulnerabilities →

Downloads (Microsoft Update Catalog)

x64 2019
799.6 MB
windows10.0-kb5078752-x64.msu Main update · KB5078752 SHA-1: d19dce98…c7a734

Updated components

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

Top changed componentsFiles
Graphics and display9
File Explorer and shell6
Networking5
Storage and file systems4
Security and sign-in3
Hyper-V and virtualization2
Kernel2
Secure Boot2
Settings2
Audio1
Bluetooth1
Magnifier1

Verified in package: changed files confirm Secure Boot.

Sources

Updated
Cited passages from Microsoft's official notes (5)
  1. 1. [File History] Improved: File History in Control Panel when backing up files. New files with names containing some Chinese and Private Use Area characters can now be backed up. support.microsoft.com
  2. 2. Devices receive new certificates only after demonstrating sufficient successful update signals, maintaining a controlled and phased rollout. support.microsoft.com
  3. 3. This servicing stack update (SSU) includes enhanced logic to verify whether a device is hosted on Azure, leveraging an updated certificate chain for validation. support.microsoft.com
  4. 4. [Windows System Image Manager] This update adds a warning dialog to help users confirm that the selected catalog file comes from a trusted source. support.microsoft.com
  5. 5. This issue is resolved in Windows updates released on and after April 14, 2026 (such as KB5082123). 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 5/5, 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