Patch tracker / KB5124006

KB5124006: Windows 11 Optional preview update (September 2026)

KB5124006 is a non-security optional preview update for Windows 11, released 2026-09-22, producing OS build 28000.3086. It closes no vulnerabilities, so it carries no Severity rank and appears in no security feed.

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Update summary

Optional preview updateNo security fixes
2026-09-22
Released
Optional preview update
Update type
28000.3086
OS build
Windows 11
Applies to

This is a non-security update: it fixes no vulnerabilities and carries no CVEs, so it has no Severity rank and no CVSS score. It is not in Microsoft's security feed, which is why most vulnerability trackers do not list it at all. Installing it is a reliability and features decision rather than a risk one.

Senserva found thiswe track every release for this product line, so we can tell you this package is behind

A newer security update for Windows 11 has shipped since this one: KB5124010 (2026-09-29). For cumulative update families the newer package includes these fixes, so installing that one is usually the shorter path. Verify against your own update rings before you skip this package.

Microsoft Update Catalog: download KB5124006Microsoft support article: what changed
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Windows release health for this update

From Microsoft's Windows release health for Windows 11, version 26H1, checked 2026-10-25. Microsoft's issue text is linked from each title.

Issues Microsoft traces to this update

Issues this update resolves

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.

CVESeverityCVSSEPSSExploited

Scope and sources

Affected products
Also released in September 2026

KB5122871

684 CVEs · Critical · exploited

KB5122876

620 CVEs · Critical · exploited

KB5122878

572 CVEs · Critical · exploited

KB5122880

608 CVEs · Critical · exploited

KB5122882

645 CVEs · Critical · exploited

KB5123065

398 CVEs · Critical · exploited

KB5123066

423 CVEs · Critical · exploited

KB5123099

559 CVEs · Critical · exploited

The full month, summarized: Microsoft Patch Tuesday.

Authoritative references
Official KB5124006 page (Microsoft Support)Microsoft Update CatalogMicrosoft Security Update Guide

See this and every Microsoft update ranked by real-world risk on the Microsoft Patch Tracker.

New to a term on this page? CVE, KB, KEV, CVSS, and EPSS are each explained once, on the Senserva security lexicon. Reference: Microsoft CVE and vulnerability management and the Microsoft patching guide.
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