Skip to content
littleden.blogEvidence-led Windows troubleshooting, without the guesswork
KB & release intelligence

Windows updates matched to version, build and known-issue state.

Use the KB number and OS build together. A symptom reported after an update is not proof that the update caused it, and later updates can change the correct resolution.

2026-08-11 · Security cumulative updateKB5121003

August 11, 2026 Windows 11 security update

The August 2026 security update for Windows 11 25H2 and 24H2. Release-health history links it to an ARM Teams/new Outlook launch issue, while a reported game-unresponsiveness cluster was later determined to be associated with RGB-related third-party drivers/components rather than Windows Update itself.

Released; several reported issues later resolved or reclassified →
2026-08-27 · Optional preview cumulative updateKB5120998

August 27, 2026 Windows 11 preview update

An optional preview cumulative update that later appeared in release-health history for desktop-background and mouse-personalization regressions on affected systems.

Released; documented personalization issues resolved by later update →
2026-09-14 · Out-of-band cumulative updateKB5129195

September 14, 2026 Windows 11 out-of-band update

A cumulative out-of-band follow-up to the September security update. It is especially relevant when troubleshooting documented RDS instability, Plan9 host-folder sharing, or multichannel USB-audio failures introduced around the September update cycle.

Released; resolves several September known issues →
2026-09-08 · Security cumulative updateKB5124008

September 8, 2026 Windows 11 security update

The September 2026 security cumulative update for Windows 11 25H2 and 24H2. Its Microsoft support record documents several post-release issues and later resolution changes, which makes build and symptom matching important before troubleshooting.

Released; follow-up OOB update available for several known issues →
Before using a KB-specific workaround: run winver or open Settings > System > About and verify the installed Windows version/build.