KB5127646: Windows 11 version 26H1 Security Update (October 2026)

Full tracking and change history for KB5127646

Released

2026-10-13

Last changed

2026-10-13

Changes tracked

1

Senserva began recording day-to-day change history on 2026-07-07, and refreshes it several times a day. Release dates are historical where Microsoft publishes them; revision history is tracked from that date forward, so it does not include changes made before then.

Check if KB5127646 is installed

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Known issues, from Microsoft

Quoted from Microsoft's support article for KB5127646 (checked 2026-10-13). Verify against the article before acting.

USB audio devices might fail to start or produce no sound

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Symptoms

After installing the September 8, 2026, Windows security update (KB5124012), some USB Audio Class 1.0 devices might fail to start or produce audio. Affected devices might experience one or more of the following symptoms:

​The device displays an error in Device Manager: "This device cannot start (Code 10).”

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No audio output.

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Volume controls are unresponsive or remain at zero.

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Sound settings are unresponsive or unavailable.

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Some devices might function in standard stereo configurations but fail when using multichannel audio features, including 8-channel or 3D audio modes. Some customers have reported that they're able to restore audio in these cases by switching to 2-channel mode.

This issue is limited to USB Audio Class 1.0 devices.

Resolution

This issue is partially resolved in the out-of-band (OOB) update released on September 14, 2026, (KB5129194) . This OOB update resolves the symptoms experienced on devices using 8-channel or 3D audio modes. Microsoft is working to address the other symptoms and will provide more information when it is available.

IT administrators who need an immediate workaround for the symptoms not addressed yet by the OOB update should contact Microsoft Support for Business for assistance.

CVEs fixed by this update

Sorted exploited-first, then by CVSS. Every CVE links to its Senserva page with the full risk facts, references, and a ready-to-paste AI prompt.