Microsoft's August 2026 Patch Tuesday addresses 421 CVEs across multiple platforms, with a critical fix targeting an actively exploited WinSock driver vulnerability. Windows 11 users are advised to install cumulative update KB5121003, which includes significant security patches and can be applied without a reboot for eligible devices. Additionally, the update addresses two TPM 2.0 hardware vulnerabilities and introduces minor user experience improvements like better File Explorer formatting. With Windows 11 version 24H2 reaching end-of-life in October 2026, IT teams must deploy these updates promptly to ensure continued support and security

Microsoft August 2026 Patch Tuesday Fixes 421 CVEs

Microsoft's August 2026 Patch Tuesday addresses a staggering 421 CVEs across Windows, Office, Exchange, SharePoint, and Azure, with the most urgent fix targeting a WinSock driver flaw actively exploited in the wild. Windows 11 users should install cumulative update KB5121003, which brings builds 26200.9168 and 26100.9168 to versions 25H2 and 24H2, while eligible devices can apply the patch hotpatch-style without a reboot. The release also quietly patches two TPM 2.0 hardware vulnerabilities and rolls out minor UX tweaks like better File Explorer unit formatting and desktop fingerprint support for Windows Hello. IT teams need to deploy these fixes immediately, especially since Windows 11 version 24H2 Home and Pro editions will lose support in just over two months.

Microsoft August 2026 Patch Tuesday Fixes 421 CVEs @ NT Compatible