- Microsoft released OOB updates for Windows 11 and Windows 10 to fix problems introduced by the September 2026 Security Update.
- The fixes address Remote Desktop failures, Hyper-V Linux folder-sharing problems, and multichannel USB Audio Class 1.0 issues.
- Windows 11 26H1, 25H2, 24H2, and 23H2 receive fixes, while Windows 10 22H2 with ESU and Enterprise LTSC 2021 also get updates.
- Some USB Audio Class 1.0 problems remain unresolved, including devices that fail to start, produce no audio, or show Code 10.
Microsoft is releasing an Out-of-band (OOB) update to address several problems introduced by the September 2026 Security Update, including Remote Desktop failures, Hyper-V folder-sharing problems, and issues affecting some USB audio devices.
The company released this community update on September 8, but some devices began experiencing problems after the installation. However, the company has now released new Out-of-band updates to address the most serious issues.
The problems affect several versions of the operating system, including Windows 11 26H1, 25H2, 24H2, and 23H2, as well as Windows 10 22H2 with Extended Security Updates. The fixes also apply to supported Windows Server releases.
For Windows 11 26H1, the company released the update KB5129194 as build 28000.2956. For Windows 11 25H2 and 24H2, the company released the update KB5129195 as builds 26200.9457 and 26100.9457.
The update addresses an issue where Remote Desktop Services could become unstable after the security update, potentially preventing new remote sessions, causing sign-in failures, or leaving the system and related tools unresponsive. Microsoft also fixed a Hyper-V problem that could prevent shared folders from appearing or being accessible inside Linux virtual machines.
The software giant also addressed a problem affecting some USB Audio Class 1.0 devices in multichannel audio modes, including 8-channel and 3D audio. However, Microsoft says other USB Audio Class 1.0 problems remain unresolved, including devices that fail to start, produce no audio, or show Code 10 in Device Manager.
Windows 11 September 2026 OOB updates
Microsoft released several Out-of-band packages depending on the version of Windows you’re running.
Windows 11 26H1 update KB5129194
- Release date: September 14, 2026.
- Builds: 28000.2956.
- Purpose: Fixes Remote Desktop Services, Hyper-V Linux virtual machine folder-sharing, and multichannel USB audio problems.
- Affected versions: Windows 11 26H1.
The update is available through Windows Update, Windows Update for Business, the Microsoft Update Catalog, and WSUS. Microsoft says it installs automatically through Windows Update and Windows Update for Business according to configured policies.
Windows 11 25H2 and 24H2 update KB5129195
- Release date: September 14, 2026.
- Builds: 26200.9457 (25H2) and 26100.9457 (24H2).
- Purpose: Fixes Remote Desktop Services, Hyper-V Linux virtual machine folder sharing, and multichannel USB audio problems.
- Affected versions: Windows 11 25H2 and 24H2.
KB5129195 is a cumulative update, so it includes previous updates along with the new fixes. You can get the update through Windows Update, Windows Update for Business, the Microsoft Update Catalog, and WSUS.
Microsoft also released KB5129241 for eligible devices enrolled in the Windows 11 hotpatch program. It applies to Windows 11 25H2 and 24H2 devices that already have the security update installed. The hotpatch build numbers are 26200.9448 and 26100.9448, and the update can take effect without requiring a restart.
Windows 11 23H2 update KB5129242
Windows 11 23H2 also received an Out-of-band update KB5129242, which brings the operating system to build 22631.7584.
Unlike the updates for 26H1, 25H2, and 24H2, this is an optional non-security update. Microsoft says it includes the security fixes and improvements from the September 8 update, plus fixes for Remote Desktop Services, Hyper-V folder sharing with Linux virtual machines, and multichannel USB audio.
If your computer is affected by these bugs, install this update immediately by going to Settings > Windows Update and clicking the “Check for updates” button.
Windows 10 gets the same fixes
Microsoft is also releasing KB5129236 for Windows 10 22H2 with ESU and Windows 10 Enterprise LTSC 2021.
The update brings Windows 10 22H2 to build 19045.7727 and Windows 10 Enterprise LTSC 2021 to build 19044.7727. It addresses the same Remote Desktop Services, Hyper-V, and USB Audio Class 1.0 problems introduced by the September security update.
KB5129236 is an Out-of-band update that includes the September security update and the additional fixes. The USB Audio Class 1.0 issue is not completely resolved, however, and Microsoft is continuing to look into the remaining symptoms.
Out-of-band (OOB) updates explained
Out-of-band updates are emergency patches released outside the regular monthly schedule. Microsoft issues them to address urgent problems (such as newly discovered security flaws or critical bugs) that can’t wait for the next Patch Tuesday.
Did the September Windows update cause problems on your PC?
Voting closes: September 21, 2026 1:00 pm
These updates are cumulative, meaning they include all previous fixes (security and non-security) plus the new targeted resolution.
Mauro Huculak is a Windows How-To Expert and founder of Pureinfotech in 2010. With over 23 years as a technology writer and IT Specialist, Mauro specializes in Windows, software, and cross-platform systems such as Linux, Android, and macOS.
Certifications: Microsoft Certified Solutions Associate (MCSA), Cisco Certified Network Professional (CCNP), VMware Certified Professional (VCP), and CompTIA A+ and Network+.
Mauro is a recognized Microsoft MVP and has also been a long-time contributor to Windows Central.
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