Microsoft released KB5129195 on September 14, 2026, as an out-of-band cumulative update for Windows 11 24H2 and 25H2. It fixes several documented September-update regressions and includes protection against CVE-2026-62721, but Microsoft does not list a Radeon graphics fix. Reported AMD freezes, black screens, driver timeouts and display-signal losses therefore remain outside the update’s documented scope.
What KB5129195 actually fixes
KB5129195 applies to all editions of Windows 11 24H2 and 25H2. After installation, systems move to build 26100.9457 on 24H2 or 26200.9457 on 25H2.
Microsoft documents fixes for Remote Desktop Services, Plan9 host-folder sharing in some HCS-managed Linux virtual machines, and selected USB Audio Class 1.0 failures. The update also addresses CVE-2026-62721, an elevation-of-privilege vulnerability in the Windows User-Mode Power Service.
| Windows component | Problem addressed | Scope of the fix |
| Remote Desktop Services | Failed connections and sign-ins, configuration hangs, and unstable administration tools | Documented RDS regression |
| Plan9 file sharing | Host-folder sharing failures in some HCS-managed Linux virtual machines | Specific Hyper-V-related virtual-machine scenario |
| USB Audio Class 1.0 | Failures affecting 8-channel and 3D-audio modes | Other USB Audio Class 1.0 symptoms remain unresolved |
The audio correction is the important fine print: KB5129195 is not a blanket fix for every USB-audio problem. Its documented scope covers specific multichannel modes.
Why the Radeon reports are a separate issue
Does KB5129195 fix AMD Radeon crashes and black screens? No confirmed Radeon fix is documented. Microsoft’s list of improvements does not include a Radeon graphics-driver repair.
Users have reported freezes, black screens, driver timeouts, lost display signals and apparent monitor-detection problems after installing KB5124008 and KB5126052. The reported hardware includes a Radeon RX 7900 XTX paired with a Ryzen 9 7900X3D and a Radeon RX 7800 XT paired with a Ryzen 7 7800X3D. One reported failing module was amdxx64.dll.
In the principal two-system account, removing both Windows updates did not restore stability. The same account says that DDU and AMD driver versions 26.8.1, 26.7.1 and 26.6.4 also failed to resolve the symptoms. Those are observations from the affected systems, not a universal rollback result or a confirmed diagnosis of the cause.
The timing has led users to associate the Radeon failures with KB5124008 and KB5126052, but that association has not been confirmed as a causal finding. KB5129195 should not be treated as an AMD graphics remedy.
Which Windows versions receive the update?
KB5129195 is available for Windows 11 24H2 and 25H2, all editions. The resulting builds are:
- Windows 11 24H2: 26100.9457
- Windows 11 25H2: 26200.9457
Microsoft lists four distribution channels: Windows Update, Windows Update for Business, WSUS and the Microsoft Update Catalog.
For Windows administrators, the practical distinction is straightforward: KB5129195 addresses the Remote Desktop, Plan9-sharing and selected USB-audio regressions Microsoft names, while the reported Radeon instability remains a separate unresolved issue.
