Microsoft Releases Emergency Windows 11 Updates to Address Security Vulnerabilities

Microsoft released out-of-band updates yesterday for Windows 11 versions 26H1, 25H2, and 24H2 to address security vulnerabilities and other issues affecting Remote Desktop Services and USB audio devices. These updates should be installed automatically on unmanaged PCs, but you can trigger the installation by checking for updates in Windows Update.

The KB5129194 patch for Windows 11 version 26H1 fixes a Windows User-Mode Power Service (UMPS) elevation-of-privilege vulnerability (CVE-2026-62721) that could allow attackers to gain system privileges. There’s also a new protection against a separate Windows User-Mode Power Service (UMPS) elevation-of-privilege vulnerability, which Microsoft also included in the KB5129195 update for Windows 11 versions 25H2/24H2, released yesterday.

Lastly, the two updates address a Remote Desktop Services (RDS) connection issue that was introduced in the September 2026 Patch Tuesday updates released last week. Microsoft also fixed problems with multichannel audio features on some USB Audio Class 1.0 devices. However, the company acknowledged that some of these devices might still fail to start or produce audio, and the company is currently working on a fix to be released in a future update.

These emergency updates include all the new features from the September 2026 Patch Tuesday release for Windows 11 users who had yet to install it. The main changes include the ability to select the Taskbar location and size, a faster Windows Search, and new customization options for the Start Menu.