Windows 10 Enterprise LTSC 2021

Build history

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update

  Out-of-band Updated Nov 13

  KB5136493 Nov 13, 2026

  Error 0x80041008 fixed for certain SLMGR licensing tasks

  Some organizations could see error 0x80041008 when using SLMGR for licensing or activation tasks; this update fixes the issue. It also improves checks for devices hosted on Azure.

  Free support for Windows 10 Enterprise LTSC 2021 ends on January 12, 2027. Organizations using it should plan for continued support.

  Key changes 3 changes

  • Improved Servicing stack: The servicing stack improves checks that identify devices hosted on Azure.
  • Fix Licensing and Activation: Some organizations could get an error while managing Windows activation or product keys. This fix applies to version 22H2.
  • Fix Licensing and Activation: Some organizations could get an error while managing Windows activation or product keys. This fix applies to version 21H2.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Updated Nov 14

  KB5131096 Nov 10, 2026

  PowerShell rejects some invalidly encoded signed scripts

  Stricter PowerShell signature checks might reject signed scripts with invalid UTF-8 encoding. The update also fixes printer setup and Remote Desktop problems.

  Check the newer update, KB5136493

  Free support for Windows 10 Enterprise LTSC 2021 ends on January 12, 2027. Plan for continued support.

  Key changes 547 CVEs · 7 changes

  • Improved Date and Time: Cuba stays on UTC-04:00 and skips the November 2026 and March 2027 clock changes. It returns to UTC-05:00 in November 2027 and resumes...
  • Improved Windows PowerShell: Some signed PowerShell scripts with invalid UTF-8 encoding might fail signature checks. Save affected scripts as valid UTF-8 with a BOM...
  • Improved Servicing stack: The latest servicing stack update comes bundled with the cumulative update.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update

  Out-of-band Updated Nov 11

  KB5134125 Oct 26, 2026

  Offline devices get updated certificate trust data

  Devices that miss automatic certificate updates get refreshed trust data in this out-of-band release. It also partly resolves USB audio problems with 8-channel and 3D audio.

  Check the newer update, KB5131096

  Free support for Windows 10 Enterprise LTSC 2021 ends January 12, 2027.

  Key changes 4 changes

  • Improved Certificates: Devices that cannot receive certificate updates automatically get a refreshed list of trusted certificates.
  • Improved Certificates: Devices that cannot receive certificate updates automatically get a refreshed list of trusted certificates.
  • Improved Servicing stack: The update process better checks whether a device is hosted on Azure, using updated security certificates.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day Updated Nov 11

  KB5126657 Oct 13, 2026

  Windows Shell flaw under active attack gets patched

  An actively exploited Windows Shell security-feature bypass gets patched, alongside changes to time zones, ReFS security, storage, and File History.

  Check the newer update, KB5134125

  Free support for Windows 10 Enterprise LTSC 2021 ends January 12, 2027. Plan for continued support before then.

  Key changes 954 CVEs · 7 changes

  • New Date and Time: A new Manitoba time zone is available.
  • New ReFS security: ReFS auditing is on by default for externally attached storage. Optional security controls are available but stay off by default.
  • Improved Date and Time: Windows adds permanent daylight saving time support for British Columbia and Alberta starting in November 2026.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update

  Out-of-band Updated Nov 11

  KB5129236 Sep 14, 2026

  Remote Desktop instability and USB multichannel audio fixed

  Fixes Remote Desktop failures, Linux VM shared-folder access, and 8-channel or 3D USB audio problems. Other USB Audio Class 1.0 symptoms remain unresolved.

  Check the newer update, KB5126657

  Free support for Windows 10 Enterprise LTSC 2021 ends January 12, 2027. Microsoft points users to its ESU guidance.

  Key changes 6 changes

  • Improved Servicing stack: The update improves how Windows checks whether a device is hosted on Azure.
  • Fix Remote Desktop Services (known issue): Remote Desktop connections and sign-ins, along with related tools, are less likely to fail or stop responding in affected environments.
  • Fix Hyper-V (known issue): Linux virtual machines can see and access folders shared from the Windows host again.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day Updated Nov 10

  KB5122878 Sep 8, 2026

  Windows ALPC flaw under attack; remote audio issue addressed

  An actively exploited Windows ALPC flaw is among the security fixes. The update also addresses Remote Desktop audio and a BitLocker recovery-key issue.

  Check the newer update, KB5129236

  Windows 10 Enterprise LTSC 2021 support ends January 12, 2027. Its users need to plan for the end of free updates and support.

  Key changes 578 CVEs · 6 changes

  • Improved Secure Boot: More eligible PCs can receive new Secure Boot certificates automatically. Certificate deployment continues over the coming months.
  • Improved Date and Time: The local time in Morocco reflects the change to permanent UTC+00:00 on September 20, 2026.
  • Improved OMA DM protocol: More debug details are saved when a device connects to a server.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day Updated Nov 10

  KB5120249 Aug 11, 2026

  Exploited Winsock driver flaw patched; File History backups fixed

  Attackers are exploiting a flaw in the Winsock Ancillary Function Driver that can let them gain higher access. Scheduled File History backups to network shares also work again.

  Check the newer update, KB5122878

  Windows 10 Enterprise LTSC 2021 support ends January 12, 2027. Windows 10, version 22H2, is available here for devices enrolled in the ESU program.

  Key changes 160 CVEs · 2 changes

  • Improved Secure Boot: More eligible PCs can automatically receive new Secure Boot certificates. Delivery continues over the coming months.
  • Fix Backup: File History scheduled backups to network shares no longer fail with an “invalid credentials” error.
  • Exploited CVE-2026-68820: Windows Ancillary Function Driver for WinSock Elevation of Privilege Vulnerability

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day Updated Nov 10

  KB5099539 Jul 14, 2026

  Shell spoofing flaw exploited; Secure Boot and RDP protections updated

  A Windows Shell spoofing flaw is already being exploited, and the update adds Secure Boot status reporting and SHA-2 support for trusted RDP publishers. Some keyboard shortcuts might stop responding in rare cases.

  Check the newer update, KB5120249

  Windows 10 Enterprise LTSC 2021 support ends January 12, 2027. Windows 10 IoT Enterprise LTSC 2021 support continues until January 13, 2032.

  Key changes 315 CVEs · 8 changes

  • New Remote Desktop (RDP) Security: Trusted Remote Desktop publishers can use SHA-2 certificates. Administrators also get guidance for controlling which Remote Desktop fil...
  • Improved Input: Hotkey cleanup behavior changes. In rare cases, some built-in Windows experiences might temporarily stop responding to keyboard shortcu...
  • Improved Secure Boot: Windows Security can now report Secure Boot status changes.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  KB5094127 Jun 9, 2026

  HTTP.sys remote-code flaw patched; Secure Boot reporting added

  Patches a critical HTTP.sys remote-code execution flaw and adds Secure Boot status reporting. File Explorer search also handles Chinese text and UTF-8 files better.

  Check the newer update, KB5099539

  Support for Windows 10 Enterprise LTSC 2021 ends January 12, 2027.

  Key changes 147 CVEs · 5 changes

  • New Secure Boot: Administrators can set a policy to limit Secure Boot data sent to Microsoft.
  • Improved File Explorer: File Explorer search handles Chinese text and UTF-8 files without a byte order mark. Text appears more clearly in search results, Conte...
  • Improved Secure Boot: Windows Security can now report Secure Boot status dynamically.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  KB5087544 May 12, 2026

  Secure Boot certificates begin expiring; Remote Desktop warning fixed

  Secure Boot certificates have started expiring in June 2026, which might affect secure booting on some devices if they are not updated in time; Microsoft recommends reviewing its preparation guidance. The update also fixes a Remote Desktop warning display issue.

  Check the newer update, KB5094127

  Windows 10 Enterprise LTSC 2021 support ends January 12, 2027. Windows 10, version 22H2, and version 21H2 have already reached their general support end dates; 22H2 updates are for ESU devices.

  Key changes 54 CVEs · 5 changes

  • New Secure Boot: Eligible devices get a SecureBoot folder with sample scripts for organizations that manage updates across a device fleet.
  • Improved Secure Boot: Windows Security can report Secure Boot status dynamically.
  • Improved Secure Boot: More eligible devices can be identified for automatic Secure Boot certificate updates, which continue to roll out in phases.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  KB5082200 Apr 14, 2026

  Critical IKE and TCP/IP remote-code flaws patched

  The update fixes 106 security flaws, including two critical remote-code execution vulnerabilities in IKE and TCP/IP. It also fixes Microsoft-account sign-in problems and adds safer handling of Remote Desktop files.

  Check the newer update, KB5087544

  Windows 10 Enterprise LTSC 2021 support ends January 12, 2027.

  Key changes 106 CVEs · 13 changes

  • New Secure Boot: The Windows Security app can report Secure Boot status dynamically and show alerts. This is disabled by default on commercial devices a...
  • New Secure Boot: The Windows Security app can report Secure Boot status dynamically and show alerts. This is disabled by default on commercial devices a...
  • Improved Remote Desktop: When you open an .rdp file, Remote Desktop shows the requested connection settings before connecting, with each setting off by default....

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  KB5078885 Mar 10, 2026

  Secure Boot certificate rollout expands; File History handles more names

  Addresses 43 Important-severity vulnerabilities and improves Secure Boot certificate targeting, File History backups, and graphics stability. Secure Boot certificates have started expiring in June 2026, so review Microsoft's guidance.

  Check the newer update, KB5082200

  Secure Boot certificates used by most Windows devices have started expiring in June 2026. Review Microsoft's guidance and update certificates in advance to help avoid disruption.

  Key changes 43 CVEs · 10 changes

  • New Windows System Image Manager: A warning helps you check that a selected catalog file comes from a trusted source.
  • New Windows System Image Manager: A warning helps you check that a selected catalog file comes from a trusted source.
  • Improved File History: File History can back up new files with names containing certain Chinese and Private Use Area characters.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day

  KB5075912 Feb 10, 2026

  Exploited Shell and MSHTML flaws patched

  Fixes 24 security vulnerabilities, including five that attackers are exploiting, and resolves a restart-on-shutdown issue affecting some Secure Launch PCs with Virtual Secure Mode enabled.

  Check the newer update, KB5078885

  Support for Windows 10 Enterprise LTSC 2021, version 21H2, ends on January 12, 2027.

  Key changes 24 CVEs · 6 changes

  • Improved Fonts: Chinese fonts are updated to meet GB18030-2022A compliance.
  • Improved Secure Boot: Devices receive new Secure Boot certificates only after showing sufficient successful update signals, supporting a phased rollout.
  • Improved Servicing stack: The update process better checks whether a device is hosted on Azure.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update

  Out-of-band

  KB5078129 Jan 24, 2026

  Cloud-file errors and Outlook hangs fixed

  Fixes errors affecting some apps that open or save cloud-stored files, including Outlook hangs in certain configurations. Some PCs with Virtual Secure Mode enabled might still restart instead of shutting down; KB5075912 resolves that issue.

  Check the newer update, KB5075912

  Windows 10 Enterprise LTSC 2021, version 21H2, reaches the end of updates on January 12, 2027.

  Key changes 2 changes

  • Improved Servicing stack: The update improves checks used to verify whether a device is hosted on Azure, supporting the installation of future updates on Azure-h...
  • Fix File System: Some applications no longer become unresponsive or encounter errors when opening files from or saving files to cloud storage. In certai...

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update

  Out-of-band

  KB5077796 Jan 17, 2026

  Remote Desktop sign-in failures fixed; cloud app hangs remain

  Remote Desktop sign-in failures are fixed, but some apps may still hang when opening or saving cloud files. The update also improves Azure checks in the servicing stack.

  Check the newer update, KB5078129

  Windows 10 Enterprise LTSC 2021 updates end on January 12, 2027.

  Known issues: 1 open

  • Apps might become unresponsive when saving files to cloud-based storage

  Key changes 2 changes

  • Improved Servicing stack: The component that installs Windows updates improves its checks for devices hosted on Azure.
  • Fix Remote Desktop: Some users can sign in to Remote Desktop again after failures with the Windows App and other Remote Desktop apps.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day

  KB5073724 Jan 13, 2026

  Exploited Desktop Window Manager flaw patched; modem drivers removed

  The update fixes 73 security vulnerabilities, including an actively exploited Desktop Window Manager flaw, and removes several modem drivers. Some Windows 10 devices might also have trouble saving files to cloud storage.

  Check the newer update, KB5077796

  Secure Boot certificates used by most Windows devices began expiring in June 2026. Certain personal and business devices might be affected if their certificates are not updated; Microsoft recommends reviewing its preparation guidance.

  Known issues: 1 open

  • Apps might become unresponsive when saving files to cloud-based storage

  Key changes 73 CVEs · 5 changes

  • Improved Credentials autofill: In certain remote support and automated sign-in workflows, credential dialogs ignore virtual keyboard input from remote desktop or scre...
  • Improved Secure Boot: Eligible devices receive new Secure Boot certificates in phases, after showing enough successful update signals.
  • Improved Servicing stack: Update installation improves verification for devices hosted on Azure.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update

  Out-of-band

  KB5074976 Dec 18, 2025

  Message Queuing disruption fixed for managed environments

  Fixes Message Queuing problems introduced by the December 9 updates, including under load in clustered environments. It is available only from the Microsoft Update Catalog.

  Check the newer update, KB5073724

  Secure Boot certificates used by most Windows devices have started expiring in June 2026. Microsoft recommends reviewing its guidance and updating certificates in advance.

  Key changes 3 changes

  • Improved Servicing stack: The component that installs Windows updates can better check whether a device is hosted on Azure.
  • Fix Message queuing (MSMQ): Message Queuing works again after problems that followed the December 9, 2025 updates. Personal devices running Windows Home or Pro are...
  • Fix Message queuing (MSMQ): Message Queuing works again after problems that followed the December 9, 2025 updates. Personal devices running Windows Home or Pro are...

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day

  KB5071546 Dec 9, 2025

  PowerShell adds a warning before running web content

  The update adds a security warning and confirmation prompt to PowerShell 5.1’s Invoke-WebRequest command. It also includes a fix for an actively exploited Cloud Files driver vulnerability.

  Check the newer update, KB5074976

  Secure Boot certificates used by most Windows devices have started expiring in June 2026. Microsoft recommends reviewing its guidance and updating certificates in advance.

  Key changes 28 CVEs · 3 changes

  • Improved PowerShell 5.1: PowerShell now warns about script execution risk and asks before continuing when you use Invoke-WebRequest.
  • Improved PowerShell 5.1: PowerShell now warns about script execution risk and asks before continuing when you use Invoke-WebRequest.
  • Improved Servicing stack: Azure-hosted devices get improved verification to help future updates install.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day

  KB5068781 Nov 11, 2025

  Closes exploited kernel flaw and fixes false support warning

  Closes 33 vulnerabilities, including the actively exploited Windows Kernel flaw CVE-2025-62215, and fixes a false end-of-support warning. Secure Boot certificates begin expiring in June 2026; Microsoft recommends reviewing its guidance and updating certificates in advance.

  Check the newer update, KB5071546

  Secure Boot certificates used by most Windows devices have started expiring in June 2026. Review Microsoft's guidance and update certificates in advance to help avoid boot-security disruption.

  Key changes 33 CVEs · 3 changes

  • Improved Servicing stack: The update improves how Azure-hosted devices are identified when installing updates.
  • Fix Update (known issue): On Windows 10, version 22H2 ESU devices, this update fixes the message that might incorrectly say Windows has reached the end of suppor...
  • Fix Update (known issue): On Windows 10 Enterprise LTSC 2021 devices, this update fixes the message that might incorrectly say Windows has reached the end of sup...

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day

  KB5066791 Oct 14, 2025

  Exploited modem and Remote Access flaws patched

  The update fixes 99 vulnerabilities, including 2 critical ones and 3 exploited flaws affecting the modem driver, IGEL OS Secure Boot, and Remote Access Connection Manager. Windows 10 support ended on October 14, 2025.

  Check the newer update, KB5068781

  Windows 10 support ended on October 14, 2025. Microsoft recommends moving to Windows 11.

  Key changes 99 CVEs · 7 changes

  • New Licensing: Azure-hosted devices get improved environment validation from an updated certificate chain in the servicing stack.
  • Improved Cryptography: RSA-based smart card certificates now use Key Storage Provider instead of Cryptographic Service Provider. Smart card authentication mig...
  • Improved File Explorer: File Explorer automatically disables previews for files downloaded from the internet, helping prevent a vulnerability when previewing p...

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  KB5065429 Sep 9, 2025

  SMB hardening support added; SMBv1 connections may fail

  Adds support for SMB hardening and fixes problems with MSI repairs and NDI streaming. SMBv1 file sharing might fail until a later update is installed.

  Check the newer update, KB5066198

  Windows 10 support ended on October 14, 2025. Microsoft recommends moving to Windows 11; Secure Boot certificates also started expiring in June 2026.

  Known issues: 1 open

  • SMBv1 protocol connectivity

  Key changes 49 CVEs · 4 changes

  • New File Server: IT administrators can deploy measures that harden SMB file sharing.
  • Improved Servicing stack: The component that installs Windows updates gets quality improvements.
  • Fix App compatibility (known issue): Some non-admin users see fewer unexpected permission prompts during MSI app installs or repairs. The change can help apps such as Offic...

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update

  Out-of-band

  KB5066188 Aug 19, 2025

  Reset and recovery failures addressed

  Addresses failures when resetting or recovering Windows 10 devices introduced by the August security update. Install it if you encountered the problem or plan to use the affected recovery methods.

  Check the newer update, KB5063842

  Support for Windows 10 ended on October 14, 2025. Microsoft recommends moving to Windows 11; after that date, Windows 10 no longer receives free updates from Windows Update, technical assistance, or security fixes.

  Key changes 3 changes

  • Improved Servicing stack: The component that installs Windows updates receives quality improvements.
  • Fix Reset and recovery: Addresses failures when resetting or recovering a Windows 10 version 21H2 device using the listed recovery methods.
  • Fix Reset and recovery: Addresses failures when resetting or recovering a Windows 10 version 22H2 device using the listed recovery methods.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  KB5063709 Aug 12, 2025

  Critical GDI+ flaw patched; reset and recovery issue resolved

  Addresses 44 vulnerabilities, including three critical flaws, and resolves a reset and recovery failure. The critical flaws affect GDI+, Microsoft Message Queuing, and Windows NTLM.

  Check the newer update, KB5066188

  Support for Windows 10 ended on October 14, 2025. Microsoft recommends moving to Windows 11.

  Key changes 44 CVEs · 5 changes

  • Improved Internal Windows OS: Internal Windows functionality receives miscellaneous security improvements.
  • Improved Windows 10, version 22H2: Version 22H2 includes the improvements from the supported version 21H2 editions.
  • Improved Internal Windows OS: Internal Windows functionality receives miscellaneous security improvements.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  KB5062554 Jul 8, 2025

  SPNEGO and Hyper-V flaws patched; CJK text may blur

  Fixes 75 vulnerabilities, including 5 critical ones. Some CJK text may look blurry at 96 DPI in Chromium-based browsers, and two input-related issues are resolved by KB5062649.

  Check the newer update, KB5062649

  Windows 10 support ended on October 14, 2025. Microsoft recommends moving to Windows 11; Secure Boot certificates have also started expiring, so devices might need certificate updates to boot securely.

  Known issues: 1 open

  • Noto fonts

  Key changes 75 CVEs · 3 changes

  • Improved Internal Windows OS: Internal Windows components receive miscellaneous security improvements; no specific user-facing change is listed.
  • Improved Internal Windows OS: Internal Windows components receive miscellaneous security improvements; no specific user-facing change is listed.
  • Improved Servicing stack: The component that installs Windows updates gets reliability improvements.

  Read update → Source: Microsoft ↗

• Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Security update

  Zero-day

  KB5060533 Jun 10, 2025

  Exploited shortcut-file flaw patched; Netlogon flaw rated critical

  The update fixes 34 vulnerabilities, including an exploited flaw in Internet Shortcut Files and a critical Netlogon flaw. It also carries an open issue that can delay delivery when organizations use quality-update deferral policies.

  Check the newer update, KB5062554

  Windows 10 support ends on October 14, 2025. Microsoft recommends moving to Windows 11.

  Known issues: 2 open

  • Noto fonts
  • Update delay with deferral policies

  Key changes 34 CVEs · 3 changes

  • Improved Internal Windows OS: Windows 10, version 21H2, gets miscellaneous security improvements to internal Windows functions; no specific issues are documented.
  • Improved Internal Windows OS: Windows 10, version 22H2, gets miscellaneous security improvements to internal Windows functions; no specific issues are documented.
  • Improved Servicing stack: The component that installs Windows updates gets quality improvements.

  Read update → Source: Microsoft ↗