Windows update intelligence

KB5124008

September security update · 2026-09-08

Curated snapshot · 2026-09-15. This small collection is not a complete risk assessment. No matching report does not mean an update is safe. Automatic monitoring is not connected.

Update identity

Windows versions: 24H2 / 25H2
OS builds: 26100.9445 / 26200.9445
Release type: Security
Released: 2026-09-08
Last checked: 2026-09-15

Read the Microsoft KB article

Issues & evidence

2 results

KB5124008ResolvedOfficial · C3

Plan9 host folders unavailable in Linux VMs

Host folders may be inaccessible in HCS-managed Linux VMs using Plan9.

WSL / Claude Cowork · Windows 11 24H2 / 25H2 · Architecture unspecified

KB5124008AcknowledgedOfficial · C3

Remote Desktop Services may become unresponsive

Some environments experience failed RDP connections or unresponsive management tools.

Remote Desktop Services · Windows 11 24H2 / 25H2 · Architecture unspecified

Resolution links

Teams and Outlook launch failures on ARM

From KB5121003 · stated scope only

Custom mouse pointers revert unexpectedly

From KB5120998 · stated scope only

Desktop background resets to a solid color

From KB5120998 · stated scope only

An update that supersedes another update does not automatically resolve every associated issue.