Microsoft KB articles
Official Windows update notes, documented: improvements, known issues, and how to get each update, with the KB number, OS build and release date at a glance.
197 articles
KB4052623: Microsoft Defender antimalware platform update (version 4.18.26050.15)
KB4052623 delivers the Microsoft Defender Antivirus antimalware platform update. Version 4.18.26050.15 is the Current Channel (Broad) release, distributed via Windows Update, WSUS, and the Microsoft Update Catalog.
KB5095091 - Windows 11 Version 26H1 Preview Update (OS Build 28000.2340)
Optional preview cumulative update for Windows 11 version 26H1, released June 23, 2026, delivering quality improvements, new features, and bug fixes at OS build 28000.2340.
KB5095093: Windows 11 Preview Update - OS Builds 26200.8737 and 26100.8737 (June 23, 2026)
Optional preview cumulative update for Windows 11 versions 25H2 and 24H2, releasing June 23, 2026, with quality improvements across Bluetooth, File Explorer, networking, and AI components.
KB5094156: Safe OS Dynamic Update for Windows 11, version 23H2 (June 9, 2026)
Safe OS Dynamic Update for Windows 11 version 23H2, released June 9, 2026. Improves the Windows Recovery Environment (WinRE) to version 10.0.22621.7219.
KB5093998: Windows 11 version 23H2 June 2026 Patch Tuesday update (OS Build 22631.7219)
Monthly security cumulative update for Windows 11 version 23H2, releasing OS build 22631.7219 on June 9, 2026.
KB5094126: Windows 11 versions 25H2 and 24H2 June 2026 Patch Tuesday update (OS Builds 26200.8655 and 26100.8655)
Monthly security cumulative update for Windows 11 versions 25H2 and 24H2, releasing OS builds 26200.8655 and 26100.8655 on June 9, 2026.
KB5094122 - Windows Server 2016 / Windows 10 1607 Security Update (OS Build 14393.9234)
Cumulative security update for Windows Server 2016 and Windows 10 version 1607, releasing OS build 14393.9234 on June 9, 2026.
June 9, 2026 - KB5094123 (OS Build 17763.8880) Security Update
Cumulative security update for Windows Server 2019 and Windows 10 Enterprise LTSC 2019, releasing OS Build 17763.8880 on June 9, 2026.
KB5094125: Windows Server 2025 June 2026 Cumulative Update (OS Build 26100.32995)
June 9, 2026 security cumulative update for Windows Server 2025, delivering OS build 26100.32995 with security fixes, Secure Boot improvements, DNS over HTTPS, and File Explorer search enhancements.
KB5094128: Windows Server 2022 June 2026 Security Update (OS Build 20348.5256)
KB5094128 is the June 9, 2026 cumulative security update for Windows Server 2022, bringing OS build to 20348.5256 with security fixes and quality improvements.
KB5095051: Windows 11 version 26H1 June 2026 Cumulative Update (OS Build 28000.2269)
June 9, 2026 security cumulative update for Windows 11 version 26H1, delivering OS build 28000.2269 with security fixes, BitLocker improvements, and folder customization hardening.
KB5094127: Windows 10 June 2026 Patch Tuesday update (OS Builds 19045.7417 and 19044.7417)
June 2026 cumulative security update for Windows 10 22H2 and 21H2 LTSC, delivering OS builds 19045.7417 and 19044.7417 with security fixes and quality improvements.
KB5089570 (OS Build 28000.2179) Preview - Windows 11 Version 26H1, May 26 2026
Optional preview cumulative update for Windows 11 version 26H1, releasing OS build 28000.2179 on May 26, 2026, with AI features, security changes, and reliability fixes.
KB5089573: Windows 11 Preview Update - OS Builds 26200.8524 and 26100.8524 (May 2026)
Optional preview cumulative update for Windows 11 versions 25H2 and 24H2, releasing May 26, 2026, with quality improvements, new features, and Secure Boot fixes.
KB5087054: Cumulative Update for .NET Framework 3.5 and 4.8.1 for Windows 11 version 24H2 (May 2026)
Security cumulative update for .NET Framework 3.5 and 4.8.1 on Windows 11 version 24H2, released May 12, 2026. Addresses two elevation of privilege CVEs.
KB5087545: Windows Server 2022 Cumulative Update (OS Build 20348.5139) - May 2026
May 12, 2026 security cumulative update for Windows Server 2022, bringing OS build to 20348.5139 with Secure Boot certificate improvements and quality fixes.
KB5087051: .NET Framework 3.5 and 4.8.1 Cumulative Update for Windows 11 25H2 and Server 24H2
May 12, 2026 security update for .NET Framework 3.5 and 4.8.1 on Windows 11 25H2 and Server 24H2, addressing two Elevation of Privilege vulnerabilities.
KB5087538 - May 12, 2026 Cumulative Security Update for Windows Server 2019 / Windows 10 LTSC 2019 (OS Build 17763.8755)
May 2026 cumulative security update for Windows Server 2019 and Windows 10 Enterprise LTSC 2019, bringing OS build 17763.8755 with Secure Boot, sign-in, RDP, and DST fixes.
KB5087544: May 12, 2026 Cumulative Security Update for Windows 10 (OS Builds 19045.7291 and 19044.7291)
May 12, 2026 cumulative security update for Windows 10 version 22H2 and 21H2 LTSC, bringing OS builds to 19045.7291 and 19044.7291 with Secure Boot and RDP fixes.
KB5087420: Windows 11 version 23H2 Security Update (OS Build 22631.7079) - May 2026
May 12, 2026 cumulative security update for Windows 11 version 23H2, bringing OS build 22631.7079 with Secure Boot, SmartScreen, and Remote Desktop fixes.