KB5078752: March 10, 2026 Security Update for Windows Server 2019 and Windows 10 LTSC 2019 (OS Build 17763.8511)

Summary

This is the March 10, 2026 cumulative security update for Windows Server 2019 and Windows 10 Enterprise LTSC 2019, bringing both products to OS Build 17763.8511. It is a monthly security update that addresses quality improvements, Secure Boot certificate targeting, and fixes for File History and Windows System Image Manager. Source: Microsoft Support.

Improvements and fixes

• Windows System Image Manager now displays a warning dialog prompting users to confirm that the selected catalog file originates from a trusted source before proceeding.
• File History in Control Panel has been improved so that files whose names include certain Chinese characters or Private Use Area characters can now be backed up successfully.
• Secure Boot certificate rollout now benefits from additional high-confidence device targeting data included in Windows quality updates. This widens the pool of devices eligible to receive updated Secure Boot certificates automatically. Targeting relies primarily on client device diagnostic data; servers have limited diagnostic data available and are therefore unlikely to qualify automatically, though they are not explicitly excluded. Devices receive the new certificates only after meeting sufficient successful update signals, keeping the rollout controlled and phased.

Known issues

Japanese characters fail to render correctly in PowerShell

Symptom: On Japanese-language installations of Windows Server 2019, after installing any update released on or after January 13, 2026, Japanese characters may not display correctly in the PowerShell console. An unintended change incorrectly sets PowerShell encoding to UTF-8 after installation. English text and command entry continue to work normally, but Japanese output appears garbled or as question marks. Japanese text entered into PowerShell is affected in the same way.

Workaround: This issue is resolved in Windows updates released on and after April 14, 2026, such as KB5082123. Microsoft recommends installing the latest Windows update for your device, as it contains important improvements and issue resolutions including this fix.

Note: Microsoft states no known issues for the Windows 10 Enterprise LTSC 2019 variant of this update at the time of writing.

How to get this update

Prerequisite: You must have the August 10, 2021 servicing stack update (KB5005112) installed before applying this cumulative update.

This update is available through the following channels:

• Windows Update - downloaded and installed automatically.
• Windows Update for Business - deployed automatically in accordance with configured policies.
• Microsoft Update Catalog - the standalone package can be downloaded directly from the Microsoft Update Catalog website.
• Windows Server Update Services (WSUS) - syncs automatically when Products and Classifications are configured as follows:
  • Product: Windows 10 LTSB, Windows Server 2019
  • Classification: Security Updates

This update includes a combined servicing stack update (SSU KB5075903, version 17763.8381) and the latest cumulative update (LCU) in a single package. Because the SSU is bundled, running wusa.exe /uninstall against the combined package will not work. To remove only the LCU, use the DISM /online /Remove-Package command with the LCU package name as the argument. The SSU cannot be removed after installation.

Frequently asked questions

Does this update apply to both Windows Server 2019 and Windows 10 Enterprise LTSC 2019?

Yes. KB5078752 applies to both Windows Server 2019 and Windows 10 Enterprise LTSC 2019, bringing both to OS Build 17763.8511. The improvements documented - including the Windows System Image Manager warning dialog, File History fix, and Secure Boot certificate targeting changes - are common to both products.

What is the end-of-support date for these products?

Microsoft will end free software updates, technical assistance, and security fixes for both Windows Server 2019 and Windows 10 Enterprise LTSC 2019 on January 9, 2029. Microsoft recommends planning an upgrade to a later version of Windows Server ahead of that date.

Are servers likely to receive the new Secure Boot certificates automatically through this update?

Not necessarily. The Secure Boot certificate targeting in this update relies primarily on client device diagnostic data. Because servers typically provide limited diagnostic data, they are unlikely to qualify for automatic certificate delivery, though they are not explicitly excluded. IT administrators should consult the Secure Boot Playbook for Windows Server for guidance.

Will this update install Microsoft Store application updates?

No. Windows updates do not install Microsoft Store application updates. Enterprise users should refer to Microsoft Store apps documentation for Configuration Manager. Consumer users can get Store app updates through the Get updates for apps and games in Microsoft Store process.