KB5078752 – Windows Server 2019

KB5078752 is the cumulative update for Windows Server 2019 and Windows Server 2019 Server Core installation. It was released on 10 March, 2026 under the ‘Patch Tuesday’ release cycle.

Salient points

• KB5078752 supersedes February 2026 cumulative update KB5075904.
• KB5078752 corresponds to Windows server build 17763.8511.
• No Zero-day vulnerabilities affect Windows Server 2019 and Windows Server 2019 Server Core installation as per March security bulletin.
• 39 security vulnerabilities have been disclosed for Macrh 2026 by Microsoft. None of these have CRITICAL severity.
• The Servicing Stack Update corresponding to KB5078752 is KB5075903 (17763.8381). It is in-built in the main cumulative update. Separate installation of the SSU or Servicing Stack is not needed. And, if you installed February patch, the SSU would be already deployed.
• KB5005112 is the SSU that must be already deployed on Windows Server 2019. If you have not deployed this SSU, please download KB5005112 and apply on the server. This is a very old SSU released in August 2021. If you have followed the update release cycle, there is a high chance that you already have this patch on the server. SSU installation does not cause server reboot.

Important Reminders

Apart from this, it is important to note that the Secure Boot certificates used by most Windows devices are set to expire starting in June 2026. Secure Boot is a security feature in Unified Extensible Firmware Interface​​​​​​​ (UEFI) based firmware that helps ensure that only trusted software runs during a device’s boot (start) sequence.

Since Windows introduced Secure Boot support, all Windows-based devices have carried the same set of Microsoft certificates in the KEK and DB. These original certificates are nearing their expiration date, and your device is affected if it has any of the listed certificate versions. To continue running Windows and receiving regular updates for your Secure Boot configuration, you will need to update these certificates.

Download KB5075903

KB5075903 is the Servicing Stack Update for Windows Server 2019 released in February 2026 alongside the main cumulative update KB5075904. It also remains the corresponding Servicing Stack Update for March cumulative update KB5078752.

If you intend to deploy cumulative updates through Windows Update or Windows Update for Business, no action is needed to install the Servicing Stack Update. The Servicing Stack Update is part of the security update that will be installed on Windows Server 2019.

For manual installation of KB5078752, there is no separate installation of KB5075903 as it is included in the main cumulative security update.

Download KB5078752

You may download the offline installer file for KB5078752 from the catalog site link shared below:

• Download KB5078752 from the Microsoft Update Catalog (799.6 MB)

Upon installation of KB5078752, the server would restart. The Servicing Stack Update is already included in the main update and will be downloaded and installed as part of the installation process.

Zero-day vulnerabilities

No zero-day vulnerability has been reported for Windows Server 2019 in March 2026.

Critical vulnerabilities

The March security bulletin for Windows Server 2019 reports 39 security vulnerabilities. There is no CRITICAL vulnerability affecting Windows Server 2019.

Changelog – KB5078752

The following changes or improvements are part of KB5078752 for Windows Server 2019:

• The update addresses security improvements for Windows Server 2019 and Windows Server 2019 Server Core installation.
• [Internal Windows OS] This update contains miscellaneous security improvements to internal Windows OS functionality. No specific issues are documented for this release.
• [Windows System Image Manager] This update adds a warning dialog to help users confirm that the selected catalog file comes from a trusted source.
• [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.
• [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.