Windows 11 KB5124008 and KB5122880: new features in the September 2026 update

Microsoft released cumulative updates KB5124008 and KB5122880 on September 8, 2026, as part of the September Patch Tuesday cycle. KB5124008 targets Windows 11 versions 24H2 and 25H2 and raises the OS build to 26200.9445 or 26100.9445. KB5122880 targets version 23H2 and raises the build to 22621.7582. Both packages deliver mandatory security fixes, but KB5124008 also rolls in the non-security changes from the August preview update KB5120998, including several user interface and platform features worth planning for.
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👉@sysadminoff

https://4sysops.com/archives/windows-11-kb5124008-and-kb5122880-new-features-in-the-september-2026-update/