Windows update intelligence

KB5124010

September optional preview · 2026-09-22

Curated snapshot · 2026-10-25. This small collection is not a complete risk assessment. No matching report does not mean an update is safe. Automatic monitoring is not connected.

Update identity

Windows versions: 24H2 / 25H2 / 26H2
OS builds: 26100.9550 / 26200.9550 / 26300.9550
Release type: Preview
Released: 2026-09-22
Last checked: 2026-10-25

Read the Microsoft KB article

Issues & evidence

1 results

KB5124010ResolvedOfficial · C3

Applications requiring AC-3 audio decoding may close unexpectedly

Legacy applications that decode AC-3 audio may close unexpectedly after the September 2026 preview.

Legacy AC-3 applications · Windows 11 24H2 / 25H2 / 26H2 · Architecture unspecified

Resolution links

Domain-joined devices may lose their secure trust relationship

From KB5124008 · stated scope only

An update that supersedes another update does not automatically resolve every associated issue.