September Patch Tuesday Arrives: Microsoft Ships Fixes Across Legacy and Current Windows Versions
Published on 09/08/2026 at 22:50 | Editorial boerse-global.de
Microsoft's monthly security release cycle landed on September 8, 2026, bringing a fresh wave of patches that stretch from the newest Windows 11 builds down to operating systems that have long exited mainstream support. The update batch covers the Edge browser, the Office suite, and the .NET Framework alongside the core Windows platforms.
For IT departments running mixed environments, the sheer spread of update packages tells its own story. Windows 11 26H1 users will find KB5124012 waiting for them, which pushes the OS build to 28000.2704. That package builds on the preview update KB5120996 that went out on August 27, 2026. The two other actively supported Windows 11 branches, 24H2 and 25H2, share the KB5124008 designation, moving them to builds 26100.9445 and 26200.9445 respectively. A preview from late August, KB5120998, served as the technical foundation there.
Windows 11 23H2, meanwhile, has KB5122880 as its designated September update. Microsoft hasn't forgotten its older install base either. The company issued KB5122878 for Windows 10 versions 21H2 and 22H2, while organizations paying for the Extended Security Update (ESU) program on Windows 10 22H2 get access to KB5126256.
Perhaps most striking is the continued attention to Windows versions that no longer receive free security fixes. KB5122876 targets Windows 10 1809, and KB5123099 covers version 1607 — both long past their official support end dates but still apparently in enough use to warrant dedicated patches.
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Beyond the usual security vulnerability closures, these updates carry a set of functional repairs. Remote Desktop users who have dealt with audio glitches during sessions may find those issues resolved. There's also a fix aimed at the Secure Boot feature, which has been a recurring focus area for the company in recent cycles.
One item that might catch travelers off guard: the updates include a time zone adjustment for Morocco. The region is scheduled to shift its clocks on September 20, 2026, and the patches prepare affected systems for that change ahead of time.
For most home users, none of this requires manual action. Windows Update handles the download and installation automatically in standard configurations. Enterprise administrators who prefer a more controlled rollout can pull the specific Knowledge Base packages directly from the Microsoft Update Catalog and distribute them through their own management tools.
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The .NET Framework also received updates in this cycle, ensuring that applications relying on the runtime stay both secure and compatible with the newly patched operating systems.
