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The Update Bureau

Windows Server

Windows Server updates

All published releases for Windows Server, newest first: what each update changes, whether to install it and any confirmed known issues. Latest release: November 13, 2026.

24 active known issues →

Windows Server updates

  • Windows Server 2019 Windows Server 2019 Security update Also for Windows 10
    Zero-day

    KB5043050

    Exploited MSHTML, Installer and Mark-of-the-Web flaws addressed

    Addresses 39 vulnerabilities, including three exploited flaws and two critical remote-code-execution vulnerabilities. It also addresses printing, BitLocker decryption and other issues on Windows Server 2019.

    As of March 31, 2026, this update is no longer available from Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.

    Key changes 39 CVEs · 6 changes

    • Improved Windows Installer: When Windows Installer repairs an application, User Account Control now prompts for credentials. Application owners need to update auto...
    • Improved Servicing stack: Includes quality improvements to the component that installs Windows updates.
    • Fix AppContainer: Addresses printer problems when you use printers in restricted settings such as AppContainer.

    Read update Source: Microsoft

    Build
    17763.6293
    Security
    39 fixed · 2 critical · 3 exploited
  • Windows Server 2016 Windows Server 2016 Security update Also for Windows 10
    Zero-day

    KB5043051

    Exploited MSHTML spoofing flaw patched; Installer repairs change

    Addresses 40 vulnerabilities, including an exploited MSHTML spoofing flaw. It also changes Windows Installer repairs so User Account Control prompts for credentials.

    As of March 31, 2026, this update is no longer available from the Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.

    Key changes 40 CVEs · 2 changes

    • Improved Windows Installer: When Windows Installer repairs an application, User Account Control now prompts for credentials. Automation scripts must be updated, an...
    • Improved Dual boot of Windows and Linux: Linux might fail to start when Windows and Linux are set up to dual-boot on a device.
    • Exploited CVE-2024-43461: Windows MSHTML Platform Spoofing Vulnerability

    Read update Source: Microsoft

    Build
    14393.7336
    Security
    40 fixed · 1 critical · 3 exploited
  • Windows Server 2022 Windows Server 2022 Security update
    Zero-day

    KB5041160

    Exploited scripting flaw patched; Linux dual-boot issue remains

    Fixes 47 vulnerabilities, including 2 critical flaws and 4 exploited vulnerabilities; a fifth vulnerability was publicly disclosed. It also adds a Secure Boot change that can prevent some Linux dual-boot systems from starting.

    Check the newer update, KB5042881
    Known issues: 2 open
    • After installing this update, you might be unable to [change your user account profile picture](https://support.microsoft.com/en-us/windows/change-your-account-picture-3645cdc7-acab-49d2-76a9-4ce7e5e…
    • After installing this security update, you might face issues with booting Linux if you have enabled the dual-boot setup for Windows and Linux in your device.

    Key changes 47 CVEs · 12 changes

    • Improved Windows Kernel Vulnerable Driver Blocklist file (DriverSiPolicy.p7b): The vulnerable driver blocklist includes more drivers at risk of being used in attacks.
    • Improved Microsoft 365 Defender: The Network Detection and Response service might have issues that interrupt network data reporting.
    • Improved BitLocker: A BitLocker recovery screen might appear at startup after installing the July 9, 2024 update; this is more likely when device encryptio...

    Read update Source: Microsoft

    Build
    20348.2655
    Security
    47 fixed · 2 critical · 4 exploited
    Restart
    Required
  • Windows Server 2019 Windows Server 2019 Security update Also for Windows 10
    Zero-day

    KB5041578

    Exploited kernel flaws addressed; Linux dual-boot issue reported

    Addresses 43 vulnerabilities, including four being exploited and one publicly disclosed. It also reports that some Windows-and-Linux dual-boot devices might fail to start Linux.

    As of March 31, 2026, this update is no longer available through the Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest Windows version.
    Known issues: 1 open
    • After installing this security update, you might face issues with booting Linux if you have enabled the dual-boot setup for Windows and Linux in your device.

    Key changes 43 CVEs · 9 changes

    • Improved Windows Kernel Vulnerable Driver Blocklist file (DriverSiPolicy.p7b): The blocklist includes more drivers at risk of Bring Your Own Vulnerable Driver attacks.
    • Improved BitLocker: Some devices might show a BitLocker recovery screen at startup after the July 9, 2024 update, especially when device encryption is on.
    • Improved Secure Boot Advanced Targeting (SBAT) and Linux Extensible Firmware Interface (EFI): The update blocks vulnerable Linux EFI bootloaders on systems running Windows. Older Linux ISO images might not boot after the update.

    Read update Source: Microsoft

    Build
    17763.6189
    Security
    43 fixed · 2 critical · 4 exploited
  • Windows Server 2016 Windows Server 2016 Security update Also for Windows 10
    Zero-day

    KB5041773

    Exploited kernel flaws patched; Linux dual-boot issue remains

    Patches 43 vulnerabilities, including flaws already exploited in attacks. Some Windows and Linux dual-boot devices might fail to boot Linux, and the update is no longer available.

    As of March 31, 2026, this update is no longer available from the Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.
    Known issues: 1 open
    • After installing this security update, you might face issues with booting Linux if you have enabled the dual-boot setup for Windows and Linux in your device.

    Key changes 43 CVEs · 6 changes

    • Improved Lock screen: The “Use my Windows user account” checkbox is no longer available on the lock screen when connecting to Wi-Fi.
    • Improved Secure Boot Advanced Targeting (SBAT) and Linux Extensible Firmware Interface (EFI): Windows blocks vulnerable Linux EFI boot managers from running. Older Linux ISO images might not boot after the update.
    • Improved Domain Name System (DNS): DNS server security is hardened to address CVE-2024-37968. Out-of-date domain configurations might cause a SERVFAIL error or timeout.

    Read update Source: Microsoft

    Build
    14393.7259
    Security
    43 fixed · 5 critical · 4 exploited
  • Windows Server 2022 Windows Server 2022 Security update
    Zero-day

    KB5040437

    Closes exploited Hyper-V and MSHTML flaws; fixes remote access issues

    Fixes 86 vulnerabilities, including two flaws already exploited in Hyper-V and the MSHTML Platform, and addresses problems with Remote Desktop, BitLocker, and other features.

    Check the newer update, KB5041160
    Known issues: 1 open
    • After installing this update, you might be unable to [change your user account profile picture](https://support.microsoft.com/en-us/windows/change-your-account-picture-3645cdc7-acab-49d2-76a9-4ce7e5e…

    Key changes 86 CVEs · 11 changes

    • Improved Double-wide character set range: PowerShell identifies and handles additional double-wide characters correctly.
    • Improved BitLocker: The default Secure Boot validation profile uses an updated set of checks for BitLocker.
    • Improved File shortcut icons: Remote paths for shortcut icons need a policy configured; without it, icons on the Start menu, desktop, and taskbar will fail to render...

    Read update Source: Microsoft

    Build
    20348.2582
    Security
    86 fixed · 4 critical · 2 exploited
    Restart
    Required
  • Windows Server 2019 Windows Server 2019 Security update Also for Windows 10
    Zero-day

    KB5040430

    Exploited MSHTML spoofing flaw patched; update no longer available

    Addresses 84 vulnerabilities, including an actively exploited MSHTML spoofing flaw. It is no longer available from Microsoft’s release channels as of March 31, 2026.

    As of March 31, 2026, this update is no longer available from the Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest Windows version.

    Key changes 84 CVEs · 6 changes

    • Improved Windows Local Administrator Password Solution (LAPS): LAPS post-authentication actions run at the end of the grace period instead of at restart.
    • Improved Remote Authentication Dial-In User Service (RADIUS) protocol: The update addresses a RADIUS issue related to MD5 collisions.
    • Improved BitLocker: BitLocker’s default Secure Boot validation profile includes additional PCR measurements.

    Read update Source: Microsoft

    Build
    17763.6054
    Security
    84 fixed · 4 critical · 1 exploited
  • Windows Server 2016 Windows Server 2016 Security update Also for Windows 10
    Zero-day

    KB5040434

    Exploited MSHTML spoofing flaw addressed; BitLocker profile changes

    Addresses an actively exploited MSHTML Platform spoofing flaw and changes the default BitLocker Secure Boot validation profile. It also updates the setup requirements for remote shortcut icons.

    As of March 31, 2026, this update is no longer available through the Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest Windows version.

    Key changes 81 CVEs · 4 changes

    • Improved Republic of Turkey name: The country's new official name is the Republic of Türkiye.
    • Improved Remote Authentication Dial-In User Service (RADIUS) protocol: The RADIUS protocol note says the issue is related to MD5 collisions and links to KB5040268 for more information.
    • Improved BitLocker: The default Secure Boot validation profile includes PCR 4, 7, and 11.

    Read update Source: Microsoft

    Build
    14393.7159
    Security
    81 fixed · 4 critical · 1 exploited
  • Windows Server 2022 Windows Server 2022 Out-of-band update
    Out-of-band

    KB5041054

    RSA signing errors addressed; profile-picture changes may fail

    Addresses an error affecting some RSA signing calls. Changing a user account profile picture might still fail on some devices.

    Check the newer update, KB5040437
    Known issues: 1 open
    • After installing this update, you might be unable to [change your user account profile picture](https://support.microsoft.com/en-us/windows/change-your-account-picture-3645cdc7-acab-49d2-76a9-4ce7e5e…

    Key changes 2 changes

    • Improved Servicing stack: The servicing stack, which installs Windows updates, receives quality improvements.
    • Fix BCryptSignHash API: The update addresses a problem that could make apps fail while signing RSA data.

    Read update Source: Microsoft

    Build
    20348.2529
    Restart
    Required
  • Windows Server 2022 Windows Server 2022 Security update
    Zero-day

    KB5039227

    Exploited Mark of the Web bypass patched; SMB access controls added

    Patches an exploited Mark of the Web security bypass and adds client-certificate access controls for SMB over QUIC.

    Check the newer update, KB5041054
    Known issues: 1 open
    • After installing this update, you might be unable to [change your user account profile picture](https://support.microsoft.com/en-us/windows/change-your-account-picture-3645cdc7-acab-49d2-76a9-4ce7e5e…

    Key changes 31 CVEs · 20 changes

    • New SMB over QUIC: Administrators can restrict which clients access SMB over QUIC servers using client-certificate authentication.
    • Improved LCU package: The update package is about 20% smaller, reducing downloads and network traffic and helping downloads on slow connections.
    • Improved curl.exe: The included curl.exe version changes to 8.7.1.

    Read update Source: Microsoft

    Build
    20348.2527
    Security
    31 fixed · 1 critical · 1 exploited
    Restart
    Required
  • Windows Server 2019 Windows Server 2019 Security update Also for Windows 10
    Zero-day

    KB5039217

    Exploited Mark of the Web bypass addressed; LSASS fixes

    The update addresses an exploited Mark of the Web security bypass, fixes two LSASS problems, and changes how Windows tags files from untrusted locations.

    As of March 31, 2026, this update is no longer available through the Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest Windows version.

    Key changes 32 CVEs · 5 changes

    • Improved curl.exe: Windows’ curl.exe is updated to version 8.7.1.
    • Improved File Explorer: Files and folders from untrusted locations get a Mark of the Web tag. This updates the LastWriteTime timestamp and might affect scenari...
    • Improved Servicing stack: The servicing stack, which installs Windows updates, receives quality improvements.

    Read update Source: Microsoft

    Build
    17763.5936
    Security
    32 fixed · 1 critical · 1 exploited
  • Windows Server 2016 Windows Server 2016 Security update Also for Windows 10
    Zero-day

    KB5039214

    Exploited Mark of the Web flaw addressed; LSASS issues fixed

    Addresses an exploited Mark of the Web security flaw and two LSASS problems on Windows servers. It also changes how files from untrusted locations are tagged.

    As of March 31, 2026, this update is no longer available from the Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.

    Key changes 28 CVEs · 3 changes

    • Improved File Explorer: Files and folders from untrusted locations get a Mark of the Web tag. Their LastWriteTime timestamp is updated, which might affect some...
    • Fix lsass.exe: LSASS stops responding on Windows servers after the April 2024 security updates.
    • Fix lsass.exe: LSASS leaks memory during a Local Security Authority (Domain Policy) Remote Protocol call.

    Read update Source: Microsoft

    Build
    14393.7070
    Security
    28 fixed · 1 critical · 1 exploited
  • Windows Server 2019 Windows Server 2019 Out-of-band update Also for Windows 10
    Out-of-band

    KB5039705

    English language pack issue affecting May 14 update installation

    Addresses an English (United States) language-pack issue that might make KB5037765 fail to install (0x800f0982 without the pack; 0x80004005 on some devices with it). It is no longer available as of March 31, 2026.

    Since March 31, 2026, this update has no longer been available from the Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.

    Key changes 2 changes

    • Improved Servicing stack: The component that installs Windows updates gets quality improvements to help devices receive and install updates reliably.
    • Fix English (United States) language pack: Addresses an issue that might make KB5037765 fail to install on devices without the English (United States) language pack. The issue mi...

    Read update Source: Microsoft

    Build
    17763.5830
  • Windows Server 2022 Windows Server 2022 Security update
    Zero-day

    KB5037782

    Closes exploited MSHTML and DWM security flaws

    Fixes 50 vulnerabilities, including two actively exploited flaws affecting MSHTML and the Desktop Window Manager. It also addresses server, networking, and IE mode issues.

    Check the newer update, KB5039227
    Known issues: 1 open
    • After installing this update, you might be unable to [change your user account profile picture](https://support.microsoft.com/en-us/windows/change-your-account-picture-3645cdc7-acab-49d2-76a9-4ce7e5e…

    Key changes 50 CVEs · 15 changes

    • Improved DNS Server: NSEC3 validation in a recursive resolver now has a default limit of 1,000 computations.
    • Improved Windows Kernel Vulnerable Driver Blocklist: The blocklist gets its quarterly update, adding drivers at risk of Bring Your Own Vulnerable Driver (BYOVD) attacks.
    • Improved Servicing stack: The update includes quality improvements to the component that installs Windows updates.

    Read update Source: Microsoft

    Build
    20348.2461
    Security
    50 vulnerabilities fixed · 2 actively exploited
    Restart
    Required
  • Windows Server 2019 Windows Server 2019 Security update Also for Windows 10
    Zero-day

    KB5037765

    Exploited DWM and MSHTML flaws patched; IE mode and VPN fixes

    Fixes 49 security vulnerabilities, including two that attackers are exploiting, and addresses problems with IE mode, VPN connections, and Windows Server features.

    As of March 31, 2026, this update is no longer available from Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.

    Key changes 49 CVEs · 8 changes

    • Improved DNS Server: NSEC3 validation in a recursive resolver now has a default limit of 1,000 computations. DNS Server administrators can change the limit.
    • Improved Windows Kernel Vulnerable Driver Blocklist: The vulnerable-driver blocklist adds drivers that are at risk of being used in BYOVD attacks.
    • Improved Servicing stack: Improves the component that installs Windows updates, helping devices receive and install Microsoft updates.

    Read update Source: Microsoft

    Build
    17763.5820
    Security
    49 vulnerabilities fixed · 2 actively exploited
  • Windows Server 2016 Windows Server 2016 Security update Also for Windows 10
    Zero-day

    KB5037763

    Exploited MSHTML and DWM flaws addressed; update expired

    Addresses 34 vulnerabilities, including two exploited flaws in MSHTML and DWM Core. It is no longer available from Microsoft’s release channels as of March 31, 2026.

    As of March 31, 2026, this update is no longer available from Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.

    Key changes 34 CVEs · 5 changes

    • Improved Supports Croatia’s change of currency from the kuna to the euro.
    • Improved DNS Server: Limits NSEC3 validation in a recursive resolver to 1,000 computations by default.
    • Fix VPN: Addresses a problem that might cause VPN connections to fail after the update dated April 9, 2024, or later.

    Read update Source: Microsoft

    Build
    14393.6981
    Security
    34 vulnerabilities fixed · 2 actively exploited
  • Windows Server 2022 Windows Server 2022 Security update
    Zero-day

    KB5036909

    Exploited proxy-driver spoofing flaw patched; server issues addressed

    The update fixes 78 Important vulnerabilities, including an actively exploited proxy-driver spoofing flaw. It also addresses high CPU usage after opening Snipping Tool and several server issues.

    Check the newer update, KB5037782
    Known issues: 1 open
    • After installing this update, you might be unable to [change your user account profile picture](https://support.microsoft.com/en-us/windows/change-your-account-picture-3645cdc7-acab-49d2-76a9-4ce7e5e…

    Key changes 78 CVEs · 20 changes

    • New Windows Hello for Business: IT admins can use MDM to turn off the prompt that appears after sign-in on an Entra-joined machine. Provisioning is off afterward for W...
    • Improved Daylight saving time: Daylight saving time changes in Palestine are supported.
    • Improved Daylight saving time: Daylight saving time changes in Kazakhstan are supported.

    Read update Source: Microsoft

    Build
    20348.2402
    Security
    78 vulnerabilities fixed · 1 actively exploited
    Restart
    Required
  • Windows Server 2019 Windows Server 2019 Security update Also for Windows 10
    Zero-day

    KB5036896

    Exploited proxy-driver flaw closed; touch keyboard issue fixed

    The update addresses 76 Important vulnerabilities, including exploited and publicly disclosed CVE-2024-26234, and fixes an issue that can keep the touch keyboard from opening.

    As of March 31, 2026, this update is no longer available from Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.

    Key changes 76 CVEs · 9 changes

    • Improved Daylight saving time: Daylight saving time changes in Palestine are supported.
    • Improved Daylight saving time: Daylight saving time changes in Kazakhstan are supported.
    • Improved Daylight saving time: Daylight saving time changes in Samoa are supported.

    Read update Source: Microsoft

    Build
    17763.5696
    Security
    76 vulnerabilities fixed · 1 actively exploited
  • Windows Server 2016 Windows Server 2016 Security update Also for Windows 10
    Zero-day

    KB5036899

    Exploited proxy driver flaw patched; Remote Desktop access fixed

    The update fixes 66 security vulnerabilities, including an exploited proxy driver spoofing flaw, and restores access to network resources from affected Remote Desktop sessions. It is no longer available as of March 31, 2026.

    As of March 31, 2026, this update is no longer available from Microsoft Update Catalog or other release channels; Microsoft recommends updating devices to the latest version of Windows.

    Key changes 66 CVEs · 4 changes

    • Improved Daylight saving time: Daylight saving time changes in Palestine are supported.
    • Improved Daylight saving time: Daylight saving time changes in Kazakhstan are supported.
    • Improved Daylight saving time: Daylight saving time changes in Samoa are supported.

    Read update Source: Microsoft

    Build
    14393.6897
    Security
    66 vulnerabilities fixed · 1 actively exploited
  • Windows Server 2019 Windows Server 2019 Out-of-band update Also for Windows 10
    Out-of-band

    KB5037425

    LSASS memory leak on domain controllers addressed

    The update addresses an LSASS memory leak that could make domain controllers stop responding and restart unexpectedly.

    Check the newer update, KB5050008

    Key changes 2 changes

    • Improved Servicing stack: Includes quality improvements to the component that installs Windows updates.
    • Fix Local Security Authority Subsystem Service (LSASS): Addresses an LSASS memory leak on domain controllers that could cause excessive memory use, stop responding, and restart unexpectedly.

    Read update Source: Microsoft

    Build
    17763.5579
    Restart
    Required
  • Windows Server 2022 Windows Server 2022 Out-of-band update
    Out-of-band

    KB5037422

    LSASS memory leak on domain controllers addressed

    Addresses an LSASS memory leak on domain controllers that could cause the service to stop responding and trigger unexpected restarts.

    Check the newer update, KB5036909

    Key changes 2 changes

    • Improved Servicing stack: The component that installs Windows updates receives quality improvements.
    • Fix Local Security Authority Subsystem Service (LSASS): An LSASS memory leak on domain controllers is addressed.

    Read update Source: Microsoft

    Build
    20348.2342
    Restart
    Required
  • Windows Server 2016 Windows Server 2016 Out-of-band update Also for Windows 10
    Out-of-band

    KB5037423

    LSASS memory leak on domain controllers addressed

    Addresses an LSASS memory leak that can cause domain controllers to stop responding and restart unexpectedly after KB5035855.

    Check the newer update, KB5046612

    Key changes 1 change

    • Fix Local Security Authority Subsystem Service (LSASS): Addresses a memory leak on domain controllers that can cause LSASS to stop responding and the servers to restart unexpectedly. The issu...

    Read update Source: Microsoft

    Build
    14393.6800
    Restart
    Required
  • Windows Server 2022 Windows Server 2022 Security update

    KB5035857

    Critical Hyper-V flaw addressed; domain controllers risk memory leaks

    The update addresses 39 vulnerabilities, including two critical Hyper-V flaws. Domain controllers might develop an LSASS memory leak; Microsoft recommends KB5037422 for domain controllers.

    Check the newer update, KB5037422

    Key changes 39 CVEs · 7 changes

    • Improved Active Directory: Active Directory domains that host MDM providers can move from Compatibility mode to Enforcement mode for strong certificate mapping.
    • Improved Explorer User Shell Folders: The device can now set and maintain the correct default permissions for user shell folders.
    • Improved Servicing stack: The component that installs Windows updates receives quality improvements.

    Read update Source: Microsoft

    Build
    20348.2340
    Security
    39 fixed · 2 critical
    Restart
    Required
  • Windows Server 2019 Windows Server 2019 Security update Also for Windows 10

    KB5035849

    Touch keyboard fix; LSASS leak can reboot domain controllers

    The update addresses a touch keyboard problem and includes 35 security fixes, including two critical Hyper-V flaws. A separate LSASS memory leak on domain controllers is addressed by KB5037425.

    As of March 31, 2026, this update is no longer available from Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest version of Windows.

    Key changes 35 CVEs · 3 changes

    • Improved Active Directory: Domains hosting mobile device management providers can transition from Compatibility mode to Enforcement mode for stronger certificate...
    • Improved Servicing stack: The component that installs Windows updates receives quality improvements.
    • Fix Touch keyboard: Addresses a problem that sometimes prevents the touch keyboard from opening.

    Read update Source: Microsoft

    Build
    17763.5576
    Security
    35 fixed · 2 critical
  • Windows Server 2016 Windows Server 2016 Security update Also for Windows 10

    KB5035855

    Domain controller memory leaks can trigger reboots; update expired

    An LSASS memory leak can crash domain controllers and trigger unscheduled reboots while they handle Kerberos requests. This update is no longer available; Microsoft recommends updating devices to the latest Windows version.

    As of March 31, 2026, this update is no longer available from Microsoft Update Catalog or other release channels. Microsoft recommends updating devices to the latest Windows version.

    Key changes 30 CVEs · 1 change

    • Improved Operating system: The update includes miscellaneous security improvements to internal operating system functionality.
    • Critical CVE-2024-21407: Windows Hyper-V Remote Code Execution Vulnerability
    • Critical CVE-2024-21408: Windows Hyper-V Denial of Service Vulnerability

    Read update Source: Microsoft

    Build
    14393.6796
    Security
    30 fixed · 2 critical