The August 2026 Windows security update is now available

The August 2026 security update is now available for all supported versions of Windows. We recommend that you install these updates promptly. For more information about the contents of this update, see the release notes, which are accessible from the Windows 11 update history page. To learn more about the different types of monthly quality updates, see Understanding Windows monthly updates.   Highlights for the Windows 11, version 25H2 update: This security update includes improvements that were part of update KB5101684 (released July 28, 2026). This update expands high confidence device targeting data, increasing coverage of devices eligible to automatically receive new Secure Boot certificates. Devices receive the new certificates only after demonstrating sufficient successful update signals, maintaining a controlled and phased rollout. This update makes quality improvements to the servicing stack, which is the component that installs Windows updates.   Short on time? Watch the Windows 11 release notes video for this month’s tips.   For instructions on how to install this update, see the KB article for your operating system listed below: Windows 11, version 26H1: KB5121000 Windows 11, versions 25H2 and 24H2: KB5121003 Windows 11, version 23H2: KB5120240 Windows 11 Enterprise LTSC 2024: Hotpatch KB5120994 Windows 10, versions 22H2 and 21H2: KB5120249 Windows 10 Enterprise LTSC 2019 and Windows Server 2019: KB5120238 Windows 10 LTSB 2016 and Windows Server 2016: KB5120418 Windows Server 2025: KB5120233 Windows Server 2025 Datacenter: Azure Edition: Hotpatch KB5120228 Windows Server 2022: KB5120242 Windows Server 2022 Datacenter: Azure Edition: Hotpatch KB5120229 Windows Server 2012 R2: KB5120385 Windows Server 2012: KB5120386   Note: With recent and upcoming Windows updates over the next few months, a limited number of consumer and business devices might experience one additional restart during installation. This one‑time restart occurs after a Secure Boot certificate update is applied as part of the Secure Boot update process. IMPORTANT: As part of the August 2026 Windows security release, separate standalone security updates are available for a limited number of devices enrolled in hotpatch updates. Affected devices will automatically install the August 2026 hotpatch update first, followed by the applicable standalone update. Installing a standalone update does not remove a device from hotpatch updates, and no re-enrollment or policy change is required. On some devices, a restart is required to complete installation, as noted below. No action is required from IT administrators and enterprise end-users as this update process will happen automatically on hotpatch-enabled devices. For more information, see the applicable KB article: Windows 11 Enterprise, versions 25H2 and 24H2: Standalone update KB5123607 Windows 11 Enterprise, versions 25H2 and 24H2 — Additional update for devices where the Pluton security processor has been configured as the TPM: KB5123273 (restart required) Windows Server 2022: KB5123303 (restart required)