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The Update Bureau

Monthly Patch Briefing

October 2026

76 updates released this month across 8 product lines · 35 Patch Tuesday · 14 out-of-band · 2 previews · 1 exploited vulnerability fixed.

Release volume

76 updates released

10 more than September (66), vs 54/mo in 2026.

Oct 2026
76
Sep 2026
66
2026 average
54/mo

Security flaws fixed

1,304 vulnerabilities

+453 flaws compared to September (851).

Oct 2026
1,304
Sep 2026
851
2026 average
364/mo

Critical & urgent

52 critical · 1 zero-day

78 critical in September, plus 14 out-of-band releases this month .

Oct critical
52
Sep critical
78
2026 average
25/mo

2026 Year-to-Date Trend

3,641 security flaws fixed across 540 updates in 2026

251 critical flaws and 16 exploited zero-days patched across the 10 published months of 2026.

Distinct security flaws fixed per month Jan – Oct 2026
October 2026
Windows 11
Monthly security update
3 out-of-band 2 previews 1,082 fixed 26 critical 1 exploited 4 with issues
1082 fixed · 26 critical Exploited CVE-2026-96951 (Windows Shell Security Feature Bypass Vulnerability)
Windows 10
Monthly security update
3 out-of-band 1,006 fixed 27 critical 1 exploited 2 with issues
1006 fixed · 27 critical Exploited CVE-2026-96951 (Windows Shell Security Feature Bypass Vulnerability)
Windows Server
Monthly security update
4 out-of-band 1,125 fixed 36 critical 1 exploited 4 with issues
1125 fixed · 36 critical Exploited CVE-2026-96951 (Windows Shell Security Feature Bypass Vulnerability)
.NET Framework
Monthly security update
21 fixed 1 critical
  • .NET 3.5 / 4.8.1 · Windows 11 26H2 KB5127694 → 3.5, 4.8.1
  • .NET 3.5 / 4.8.1 · Windows 11 26H1 KB5127691 → 3.5, 4.8.1
  • .NET 3.5 / 4.8.1 · Windows 11 24H2/25H2, Windows Server 2025 KB5127690 → 3.5, 4.8.1
  • .NET 3.5 / 4.8.1 · Windows 11 23H2 KB5127692 → 3.5, 4.8.1
+7 more KB5127689 3.5, 4.8.1 · KB5127693 3.5, 4.8.1 · KB5127683 3.5, 4.8 · KB5127687 3.5, 4.8 · KB5127685 3.5, 4.8 · KB5127684 4.8 · KB5127666 3.5, 4.7.2
21 fixed · 1 critical

Vulnerabilities fixed, by version

Product Version Monthly update & build Critical Important Total
Windows 11
Windows 11, version 26H2 KB5127648 26300.9711 25 1042 1,067
Windows 11
Windows 11, version 26H1 KB5127646 28000.3231 25 1030 1,055
Windows 11
Windows 11, version 25H2 KB5127648 26200.9711 25 1042 1,067
Windows 11
Windows 11, version 24H2 KB5127648 26100.9711 25 1042 1,067
Windows 11
Windows 11, version 23H2 KB5126653 22631.7652 25 996 1,021
Windows 10
Windows 10 Enterprise LTSC 2019 KB5126651 17763.9376 24 922 946
Windows 10
Windows 10 Enterprise LTSB 2016 KB5126868 14393.9612 20 728 748
Windows 10
Windows 10, version 22H2 KB5126657 19045.7807 22 932 954
Windows 10
Windows 10 Enterprise LTSC 2021 KB5126657 19044.7807 22 932 954
Windows Server
Windows Server 2025 KB5126646 26100.33650 35 1062 1,098
Windows Server
Windows Server 2022 KB5126655 20348.5761 33 1000 1,034
Windows Server
Windows Server 2019 KB5126651 17763.9376 30 939 970
Windows Server
Windows Server 2016 KB5126868 14393.9612 26 740 767
.NET Framework
.NET Framework 4.8.1 KB5127694 4.8.10008.0 1 18 21
.NET Framework
.NET Framework 4.8 KB5127683 4.8.4811.0 1 18 21
.NET Framework
.NET Framework 4.7.2 KB5127666 4.7.4150.0 1 18 21
.NET Framework
.NET Framework 3.5 KB5127694 2.0.50727.9188 1 18 21
SQL Server
SQL Server 2025 KB5126967 17.0.5015.4 · 23 29
SQL Server
SQL Server 2022 KB5126934 16.0.4305.5 · 18 23
SQL Server
SQL Server 2019 KB5128494 15.0.4500.2 · 16 21
SQL Server
SQL Server 2017 KB5128496 14.0.3560.2 · 9 14
SharePoint Server
SharePoint Server Subscription Edition KB5002927 16.0.20326.20190 2 36 39
Office Online Server
Office Online Server KB5002928 16.0.10417.20228 13 31 44
Exchange Server
Exchange Server Subscription Edition KB5128895 15.2.2562.56 1 6 15
Exchange Server
Exchange Server 2019 KB5128896 15.2.1748.55 1 6 16
Exchange Server
Exchange Server 2016 KB5128898 15.1.2507.77 1 6 15

All updates

All updates:
  • Windows 11 · Future platforms
    Windows 11 Windows 11 Insider Future platforms Insider Preview
    Experimental Channel
    Build 29698.1000

    Desktop app privacy controls and taskbar settings across monitors

    Desktop apps get separate camera, microphone, and location controls, while taskbar settings better keep their state across monitor changes. These changes are rolling out to Windows Insiders in the Experimental Channel.

    Changes 1 new · 2 improved · 1 fix
  • Windows 11 · 26H1
    Windows 11 Windows 11 Insider 26H1 Insider Preview
    Experimental Channel
    Build 28120.3393

    Windows Search adds phone actions and AutoPlay gets a new look

    Windows Search adds controls, phone actions, richer results, and filters; AutoPlay gets a refreshed dialog. These changes are rolling out gradually to Experimental Channel Insiders.

    Changes 5 new · 11 improved · 1 fix
  • Windows 11 · 26H1
    Windows 11 Windows 11 Insider 26H1 Insider Preview
    Beta Channel
    Build 28020.3382

    Search controls, Cloud rebuild drive erasure, and refreshed AutoPlay

    Search gets clearer results and web-suggestion controls, while Cloud rebuild adds drive erasure and remote setup. AutoPlay is refreshed; these changes are rolling out gradually to Beta Channel Insiders.

    Changes 3 new · 4 improved
  • Windows 11 · 26H2
    Windows 11 Windows 11 Insider 26H2 Insider Preview
    Experimental Channel
    Build 26340.9843

    Windows Search phone actions and shared family storage in Settings

    Windows Search gains phone actions, and Settings shows shared Microsoft 365 Family storage use. These changes are rolling out gradually to Experimental Channel Insiders.

    Changes 9 new · 3 improved
  • Windows 11 · 25H2
    Windows 11 Windows 11 Insider 25H2 Insider Preview
    Beta Channel
    Build 26220.9836

    Per-app privacy controls and clearer security key sign-in

    Per-app camera, microphone, and location controls arrive alongside a clearer security key PIN screen. Mouse personalization and wallpaper reset issues are fixed for Beta Channel Insiders.

    Changes 2 new · 4 improved · 1 fix
  • Windows 11 · 25H2, 26H2
    Windows 11 25H2 / 26H2 Windows 11 25H2 / 26H2 Optional preview
    Preview Updated
    KB5127936

    File Explorer gains a customizable menu; recovery adds cloud rebuild

    File Explorer gets a faster, customizable right-click menu, and Windows adds Cloud rebuild for recovery. The preview also fixes Remote Desktop failures for some non-admin users.

    Builds 26200.9818 26300.9818
    Replaced by KB5132061 →
  • Windows 11 · 26H1
    Windows 11 26H1 Windows 11 26H1 Optional preview
    Preview Updated
    KB5127653

    DPAPI prompt warning and new touchpad gestures

    A warning flags the planned April 2027 retirement of prompt-based DPAPI protection. New touchpad gestures, Emoji 17.0, and other Windows features also arrive in this optional preview.

    Build 28000.3365
    Replaced by KB5132059 →
  • Windows 11 · 24H2, 25H2, 26H2
    Windows 11 24H2 / 25H2 / 26H2 Windows 11 24H2 / 25H2 / 26H2 Out-of-band update
    Out-of-band Updated
    KB5134133

    Offline PCs get trusted certificate updates; Smart App Control can fail

    Devices that miss automatic certificate updates receive updated trusted root certificates. Some devices might be unable to turn Smart App Control back on after it was disabled.

    Builds 26100.9725 26200.9725 26300.9725
    Replaced by KB5127936 →
  • Windows 11 · 26H1
    Windows 11 26H1 Windows 11 26H1 Out-of-band update
    Out-of-band
    KB5134134

    Offline devices receive updated trusted root certificates

    Devices that miss automatic certificate trust updates get an updated trusted-root payload. The package also updates AI components and improves update installation reliability.

    Build 28000.3237
    Replaced by KB5127653 →
  • Windows 11 · 23H2
    Windows 11 23H2 Windows 11 23H2 Out-of-band update
    Out-of-band Updated
    KB5134130

    23H2 Enterprise and Education updates end November 10

    Windows 11 version 23H2 Enterprise and Education reach the end of updates on November 10, 2026.

    Build 22631.7654
    Replaced by KB5131087 →
  • Windows 10 · 21H2, 22H2
    Windows 10 21H2 / 22H2 Windows 10 21H2 / 22H2 Out-of-band update
    Out-of-band Updated
    KB5134125

    Offline devices get updated certificate trust data

    Devices that miss automatic certificate updates get refreshed trust data in this out-of-band release. It also partly resolves USB audio problems with 8-channel and 3D audio.

    Builds 19044.7811 19045.7811
    Replaced by KB5131096 →
  • Windows 10 · 1809
    Windows 10 1809 Windows 10 1809 Out-of-band update Also for Windows Server
    Out-of-band Updated
    KB5134124

    Updated trusted-root certificates for disconnected devices

    Devices that miss automatic certificate trust updates get an updated trusted-root certificate payload. This out-of-band release is intended for systems that cannot reach Microsoft's certificate service or have automatic updates disabled.

    Build 17763.9378
    Replaced by KB5131085 →
  • Windows 10 · 1607
    Windows 10 1607 Windows 10 1607 Out-of-band update Also for Windows Server
    Out-of-band Updated
    KB5134123

    Offline devices get updated trusted certificates

    Devices that cannot reach Microsoft’s certificate service get updated trusted certificate data. Support for this edition ended October 13, 2026.

    Build 14393.9615
    Replaced by KB5131291 →
  • Windows Server · 2025
    Windows Server 2025 Windows Server 2025 Out-of-band update
    Out-of-band Updated
    KB5134137

    Offline servers get updated trusted root certificates

    Devices that cannot reach Microsoft's certificate-update service get an updated trusted root certificate payload. Hotpatch-enrolled devices that install this update will not receive hotpatch updates until after they install the January 2027 baseline.

    Build 26100.33674
    Known issues 1 open
    Replaced by KB5131080 →
  • Windows Server · 2022
    Windows Server 2022 Windows Server 2022 Out-of-band update
    Out-of-band Updated
    KB5134140

    Root certificates updated for isolated servers; Exchange mail can fail

    An updated trusted root certificate list helps servers that cannot reach Microsoft's certificate service. Some on-premises Exchange servers might also have trouble with sign-in and mail delivery.

    Build 20348.5773
    Known issues 1 open
    Replaced by KB5131090 →
  • Windows Server · 2019
    Windows Server 2019 Windows Server 2019 Out-of-band update Also for Windows 10
    Out-of-band Updated
    KB5134124

    Updated root certificate payload for disconnected devices

    Devices that cannot get certificate updates from Microsoft receive an updated trusted root certificate payload. Some Exchange servers might still have sign-in and email problems.

    Build 17763.9378
    Replaced by KB5131085 →
  • Windows Server · 2016
    Windows Server 2016 Windows Server 2016 Out-of-band update Also for Windows 10
    Out-of-band Updated
    KB5134123

    Certificate trust updates for isolated devices; Exchange issues remain

    Devices that cannot get certificate trust updates receive a refreshed trusted root certificate list. Some on-premises Exchange servers might still have OWA sign-in or email delivery problems.

    Build 14393.9615
    Replaced by KB5131291 →
  • Windows 11 · Future platforms
    Windows 11 Windows 11 Insider Future platforms Insider Preview
    Experimental Channel
    Build 29695.1001

    Magnifier contrast themes and VMware green-screen fix

    Adds a lower-glare contrast theme in Magnifier and fixes several network, virtual machine, and VMware issues. Recall may be missing or unable to launch on some Copilot+ PCs after a clean install.

    Changes 1 new · 2 improved · 4 fixes
  • Windows 11 · 26H1
    Windows 11 Windows 11 Insider 26H1 Insider Preview
    Experimental Channel
    Build 28120.3302

    Customizable Start menu and per-screen Magnifier controls

    Adds Start menu options, desktop-app privacy controls, and new Magnifier features. A clean install might leave Recall missing or unable to launch on some Copilot+ PCs.

    Changes 6 new · 5 improved
  • Windows 11 · 26H1
    Windows 11 Windows 11 Insider 26H1 Insider Preview
    Beta Channel
    Build 28020.3292

    Unicode 17.0 text support and a Recall install issue

    Build 28020.3292 gradually adds support for Unicode 17.0 text shaping for Beta Channel Insiders. Recall may be missing or fail to launch on some Copilot+ PCs after a clean install.

    Changes 1 new
  • Windows 11 · 26H2
    Windows 11 Windows 11 Insider 26H2 Insider Preview
    Experimental Channel
    Build 26340.9767

    Phone controls and internet speed tests in Quick Settings

    Experimental Channel Insiders are testing phone controls and internet speed tests in Quick Settings, alongside changes to Magnifier, subscriptions, and several Windows components.

    Changes 4 new · 4 improved · 2 fixes
  • Windows 11 · 25H2
    Windows 11 Windows 11 Insider 25H2 Insider Preview
    Beta Channel
    Build 26220.9757

    File Explorer gets a customizable context menu

    Build 26220.9757 is rolling out to Beta Channel Insiders with a customizable File Explorer context menu and a first-time tip; the Settings home page should load faster in some scenarios.

    Changes 2 new · 1 improved
  • SQL Server · CU10
    SQL Server 2025 CU10 SQL Server 2025 CU10 Cumulative update
    Updated
    KB5125471

    Recovery checks can trigger access violations

    Queries against `sys.dm_exec_requests` during database recovery can trigger access violations and dump files. CU10 also leaves open an issue where parallel `SESSION_CONTEXT` queries can return wrong results.

    Build 17.0.5035.5
    Known issues 2 open
    Replaced by KB5129299 →
  • Windows 11 · 26H1
    Windows 11 Windows 11 Insider 26H1 Insider Preview
    Experimental Channel
    Build 28120.3272

    Search controls and a new Pointer Indicator setting

    Build 28120.3272 is rolling out Search changes, Pointer Indicator, and other improvements to the Experimental Channel. It also fixes crashes in some apps and games.

    Changes 2 new · 5 improved · 1 fix
  • Windows 11 · 26H1
    Windows 11 Windows 11 Insider 26H1 Insider Preview
    Beta Channel
    Build 28020.3262

    Clearer Family Safety messages and an app crash fix

    Beta Channel Insiders get clearer messages when parental controls block apps and a fix for crashes in some apps and games.

    Changes 1 improved · 1 fix