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.NET Framework October 2026 cumulative update

Released October 13, 2026

Summary of what's new in this release

Security improvements

CVE-2026-58280 – Denial of Service vulnerability

This security update addresses a denial of service vulnerability detailed in CVE-2026-58280.

CVE-2026-69439 – Elevation of Privilege vulnerability

This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-69439.

CVE-2026-69651 – Denial of Service vulnerability

This security update addresses a denial of service vulnerability detailed in CVE-2026-69651.

CVE-2026-70007 – Remote Code Execution vulnerability

This security update addresses a remote code execution vulnerability detailed in CVE-2026-70007.

CVE-2026-70035 – Remote Code Execution vulnerability

This security update addresses a remote code execution vulnerability detailed in CVE-2026-70035.

CVE-2026-70174 – Remote Code Execution vulnerability

This security update addresses a remote code execution vulnerability detailed in CVE-2026-70174.

CVE-2026-83520 – Remote Code Execution vulnerability

This security update addresses a remote code execution vulnerability detailed in CVE-2026-83520.

CVE-2026-84008 – Denial of Service vulnerability

This security update addresses a denial of service vulnerability detailed in CVE-2026-84008.

CVE-2026-85363 – Elevation of Privilege vulnerability

This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-85363.

CVE-2026-87697 – Remote Code Execution vulnerability

This security update addresses a remote code execution vulnerability detailed in CVE-2026-87697.

CVE-2026-96222 – Spoofing vulnerability

This security update addresses a spoofing vulnerability detailed in CVE-2026-96222.

CVE-2026-96224 – Remote Code Execution vulnerability

This security update addresses a remote code execution vulnerability detailed in CVE-2026-96224.

CVE-2026-96233 – Denial of Service vulnerability

This security update addresses a denial of service vulnerability detailed in CVE-2026-96233.

CVE-2026-96958 – Denial of Service vulnerability

This security update addresses a denial of service vulnerability detailed in CVE-2026-96958.

CVE-2026-96959 – Denial of Service vulnerability

This security update addresses a denial of service vulnerability detailed in CVE-2026-96959.

CVE-2026-96960 – Denial of Service vulnerability

This security update addresses a denial of service vulnerability detailed in CVE-2026-96960.

CVE-2026-97788 – Information Disclosure vulnerability

This security update addresses an information disclosure vulnerability detailed in CVE-2026-97788.

CVE-2026-97801 – Tampering vulnerability

This security update addresses a tampering vulnerability detailed in CVE-2026-97801.

CVE-2026-108398 – Security Feature Bypass vulnerability

This security update addresses a security feature bypass vulnerability detailed in CVE-2026-108398.

Quality and reliability improvements

This release contains no new quality and reliability improvements.

Known issues in this release

This release contains no known issues.

Summary tables

The following table outlines the updates in this release.

Product version Cumulative update
Windows 11, version 26H2
.NET Framework 3.5, 4.8.1 5127694
Windows 11, version 26H1
.NET Framework 4.8.1 5127691
Windows 11, version 25H2
.NET Framework 3.5, 4.8.1 5127690
Windows 11, version 24H2
.NET Framework 3.5, 4.8.1 5127690
Windows 11, version 23H2
.NET Framework 3.5, 4.8.1 5127692
Windows Server 2025
.NET Framework 3.5, 4.8.1 5127690
Windows Server 2022
.NET Framework 3.5, 4.8 5127687
.NET Framework 3.5, 4.8.1 5127693
Windows 10, version 22H2
.NET Framework 3.5, 4.8 5127683
.NET Framework 3.5, 4.8.1 5127689
Windows 10, version 21H2
.NET Framework 3.5, 4.8 5127683
.NET Framework 3.5, 4.8.1 5127689
Windows 10 1809 and Windows Server 2019
.NET Framework 3.5, 4.7.2 5127666
.NET Framework 3.5, 4.8 5127685
Windows 10 1607 and Windows Server 2016
.NET Framework 3.5, 4.6.2, 4.7, 4.7.1, 4.7.2 5126868 (included in the LCU)
.NET Framework 4.8 5127684

The following table is for earlier Windows Server versions for Security and Quality Rollup updates.

Product version Security and quality rollup
Windows Server 2012 R2
.NET Framework 3.5 5127664
.NET Framework 4.6.2, 4.7, 4.7.1, 4.7.2 5127668
.NET Framework 4.8 5127688
Windows Server 2012
.NET Framework 3.5 5127660
.NET Framework 4.6.2, 4.7, 4.7.1, 4.7.2 5127667
.NET Framework 4.8 5127686

The operating system rows list a KB that's used for update-offering purposes. When the operating system KB is offered, the applicability logic determines the specific .NET Framework updates that will be installed. Updates for individual .NET Framework versions are installed based on the version of .NET Framework that's already present on the device. Because of this, the operating system KB is not expected to be listed as an installed update on the device. The expected updates to be installed are the .NET Framework specific version updates listed in the preceding table.

This update installs the complete .NET Framework 3.5 product for Windows 11, version 26H1 (build version 28000) and newer. Unlike traditional cumulative updates that patch individual components, this update delivers the full .NET Framework 3.5 product as a standalone installer. It replaces any previously installed version.

Product version .NET Framework 3.5 product update
.NET Framework 3.5 5127696