🔵Microsoft has issued out-of-band cumulative updates KB5129194 for Windows 11 version 26H1 and KB512

🔵Microsoft has issued out-of-band cumulative updates KB5129194 for Windows 11 version 26H1 and KB5129195 for Windows 11 versions 25H2 and 24H2, aiming to fix problems introduced by the monthly updates rolled out on September 8, 2026.

On the security front, Microsoft patched privilege-escalation vulnerabilities in Windows User-Mode Power Service and, on 26H1, Windows Secure Kernel Mode. For regular users, the more practical fixes address problems in Remote Desktop Services, Hyper-V, and audio.

RDS had been causing connection failures, login issues, and unresponsive management tools after the September update. Hyper-V users also saw crashes when sharing folders with Linux VMs through Plan9. Microsoft additionally fixed a bug affecting some USB Audio Class 1.0 devices in multichannel audio modes.

One known issue remains: some USB Audio Class 1.0 devices may fail to start or produce sound after the September update. If you rely on remote access, virtual machines, or older USB audio gear, this patch is worth installing now.