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Windows Server 2019 Windows Server 2019 Security update
Patch Tuesday Zero-day

KB5075904

KB5075904: Cumulative update for Windows Server, version 2019, February 2026. Exploited Shell and MSHTML security bypasses patched

In short

Fixes 24 vulnerabilities, including five that attackers are exploiting. It also fixes shutdown, folder-name, and graphics problems.

Does it affect you? Applies to: Devices running Windows Server 2019, x64.

Build
17763.8389
Security
24 fixed · 5 exploited
Restart
Required
Review notes Additional details from the official release notes (1) Read note
  • What changes This update fixes an issue where some PCs with Secure Launch and Virtual Secure Mode enabled restarted instead of shutting down or entering hibernation.

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

Microsoft publishes separate notes for this KB for Windows 10.

What changes

Fixes 3 changes

OS Security

For: Devices with Secure Launch and Virtual Secure Mode enabled

  • Some Secure Launch-capable PCs with Virtual Secure Mode enabled can shut down or hibernate instead of restarting.1

Folders

  • Custom folder names appear as expected in File Explorer when folders are renamed with desktop.ini files.2
    The LocalizedResourceName setting was ignored.

Graphics

For: Devices with certain GPU configurations

  • Improves stability for certain graphics processing unit configurations.3

Improvements 2 changes

Fonts

For: Users of Chinese fonts

  • Chinese fonts are updated to meet GB18030-2022A compliance.4

Servicing stack

  • The update includes quality improvements to the component that installs Windows updates.5
    Includes servicing stack update KB5075903, build 17763.8381.

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 installing updates released on or after January 13, 2026. Updates released on or after April 14, 2026, including KB5082123, resolve the issue.6

    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
2026-02-10
Classification
Security Updates
Type
Cumulative update
Restart
Required
Replaces
KB5078131, KB5077795, KB5073723, KB5074975
+15 earlier KB5071544, KB5068791, KB5070883, KB5066586, KB5065428, KB5066187, KB5063877, KB5062557, KB5060531, KB5061978, KB5058392, KB5059091, KB5058922, KB5050008, KB5037425
Replaced by
KB5078752
VersionBuildChannel
2019 17763.8389 General availability

Security

24 vulnerabilities fixed
5 exploited 23 important 1 moderate
VulnerabilitySeverityCVSS
CVE-2026-21510 Exploited
Windows Shell Security Feature Bypass Vulnerability
 Important 8.8
CVE-2026-21513 Exploited
MSHTML Framework Security Feature Bypass Vulnerability
 Important 8.8
CVE-2026-21519 Exploited
Desktop Window Manager Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-21533 Exploited
Windows Remote Desktop Services Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-21525 Exploited
Windows Remote Access Connection Manager Denial of Service Vulnerability
 Moderate 6.2
CVE-2026-21255
Windows Hyper-V Security Feature Bypass Vulnerability
 Important 8.8
CVE-2026-21231
Windows Kernel Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-21236
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-21238
Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-21239
Windows Kernel Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-21240
Windows HTTP.sys Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-21246
Windows Graphics Component Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-21251
Cluster Client Failover (CCF) Elevation of Privilege Vulnerability
 Important 7.8
CVE-2026-20846
GDI+ Denial of Service Vulnerability
 Important 7.5
CVE-2026-21243
Windows Lightweight Directory Access Protocol (LDAP) Denial of Service Vulnerability
 Important 7.5
CVE-2026-21235
Windows Graphics Component Elevation of Privilege Vulnerability
 Important 7.3
CVE-2026-21244
Windows Hyper-V Remote Code Execution Vulnerability
 Important 7.3
CVE-2026-21247
Windows Hyper-V Remote Code Execution Vulnerability
 Important 7.3
CVE-2026-21248
Windows Hyper-V Remote Code Execution Vulnerability
 Important 7.3
CVE-2026-21234
Windows Connected Devices Platform Service Elevation of Privilege Vulnerability
 Important 7.0
CVE-2026-21253
Mailslot File System Elevation of Privilege Vulnerability
 Important 7.0
CVE-2026-21508
Windows Storage Elevation of Privilege Vulnerability
 Important 7.0
CVE-2026-21222
Windows Kernel Information Disclosure Vulnerability
 Important 5.5
CVE-2026-21249
Windows NTLM Spoofing Vulnerability
 Important 3.3

Downloads (Microsoft Update Catalog)

x64 2019
711.5 MB
windows10.0-kb5075904-x64.msu Main update · KB5075904 SHA-1: 2e5ebd48…a8b56f

Updated components

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

Top changed componentsFiles
Networking9
Graphics and display8
Hyper-V and virtualization5
Remote Desktop5
Bluetooth4
Search4
Secure Boot4
Storage and file systems4
File Explorer and shell3
Kernel3
Security and sign-in3
Windows Update3

Sources

Updated
Cited passages from Microsoft's official notes (6)
  1. 1. Fixed: After installing the Windows security update released on or after January 13, 2026, some Secure Launch-capable PCs with Virtual Secure Mode (VSM) enabled are unable to shut down or enter hibernation. Instead, the device restarts. support.microsoft.com
  2. 2. The LocalizedResourceName setting was ignored, so custom folder names did not show. Now, custom folder names appear as expected. support.microsoft.com
  3. 3. Fixed: A stability issue affecting certain graphics processing units (GPUs) configurations. support.microsoft.com
  4. 4. This update includes changes to Chinese fonts to meet GB18030-2022A compliance. support.microsoft.com
  5. 5. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. support.microsoft.com
  6. 6. 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, 6 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 3/5, 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