Microsoft fixes audio issues caused by September security updates

Microsoft says the November 2026 cumulative updates resolve USB audio issues plaguing Windows users who have installed security updates released since September.

The company explained, when it acknowledged this known issue days after the September 2026 Patch Tuesday, that USB Audio Class 1.0 devices failed to start or produce audio on some systems after installing recent updates.

Microsoft released out-of-band updates on September 14 to fix the symptoms experienced on devices using 8-channel or 3D audio modes and has now addressed the remaining issues in security updates released as part of this month's Patch Tuesday.

Two years ago, Microsoft also confirmed an issue that caused game audio to unexpectedly increase to full volume when using USB DAC sound systems and blocked Windows 24H2 upgrades on systems with incompatible Intel Smart Sound Technology (SST) audio drivers due to blue screen of death (BSOD) issues.

errors in Device Manager, while others said the impacted USB audio speakers fail only when using multichannel audio features, including 3D audio or 8-channel modes.

These audio issues affect both server (Windows Server 2012 and later) and client (Windows 10 and Windows 11) systems.

While Microsoft has yet to provide an official workaround for those who can't immediately install the November 2026 security updates, some users have restored audio on affected Windows PCs by switching to 2-channel mode.

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Microsoft said in a Windows release health dashboard update.

In January 2025, Microsoft addressed a similar issue triggered by the KB5050094 optional preview cumulative update, which caused audio playback issues and Code 10 errors on Windows 11 24H2 systems with USB audio device drivers.

More recently, in September 2025, it lifted a safeguard hold preventing Windows 11 24H2 upgrades on systems with Dirac audio improvement software because compatibility issues caused Bluetooth speakers and headsets to malfunction.

With the November 2026 cumulative updates, Microsoft also resolved Outlook sign-in and mail delivery issues on Exchange Server systems triggered by the October 2026 Windows Server security updates.