KB5127648BMonthly security release (Patch Tuesday) · 2026-10 B

Monthly security release (Patch Tuesday) for Windows 11, version 26H2 and 2 more versions

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Pilot firstKB5127648B

Released in the last few days. Start with a pilot ring while early reports come in.

ChangeIntel's reading of public signals, not advice; check Microsoft's guidance and test before you deploy. Terms

UrgencyUnknown · evidence incomplete RiskUnknown · evidence incomplete

Resolves 2 earlier known issues
Released today
Some required public sources could not be fully read. The assessment may be missing issues or security fixes.

3Windows versions

Security evidence incomplete: Some required public sources could not be fully read. The assessment may be missing issues or security fixes.

From Microsoft's release-information tables

Servicing branch	OS build	Release	Available
Windows 11, version 26H2	26300.9711	B 2026-10 B	13 Oct 2026
Windows 11, version 25H2	26200.9711	B 2026-10 B	13 Oct 2026
Windows 11, version 24H2	26100.9711	B 2026-10 B	13 Oct 2026

Windows release health

Windows release health lists no issues from this KB or the update it builds on in the collected data.

Resolvedfrom KB5124010 fixed by KB5127648Win 11 25H2, Win 11 24H2updated 13 Oct

Applications which require AC-3 audio decoding might close unexpectedlyThis issue is more likely to occur in legacy applications, and unlikely for many modern applications.
Resolvedfrom KB5120996 fixed by KB5127646Win 11 26H1, Win 11 25H2, Win 11 24H2updated 13 Oct

Devices might experience a black screen or desktop loading issues after sign-inMicrosoft has received reports of this issue occurring in some virtual desktop environments.