October 13, 2026-KB5128923 Cumulative Update for .NET Framework 3.5, 4.7.2 and 4.8 for Windows 10, version 1809 and Windows Server 2019

Applies To
.NET

Note

  • Release Date:
    October 13, 2026
  • Version:
    .NET Framework 3.5, 4.7.2 and 4.8

Summary

This article describes the security and cumulative update for 3.5, 4.7.2 and 4.8 for Windows 10, version 1809 and Windows Server 2019.

Security Improvements

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

CVE-2026-62886 - .NET Framework Elevation of Privilege vulnerability
This security update addresses an elevation of privilege vulnerability detailed in CVE-2026-62886.

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

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

CVE-2026-70007 - .NET Framework Remote Code Execution vulnerability
This security update addresses a remote code execution vulnerability detailed in CVE-2026-70007.

CVE-2026-70035 - .NET Framework Remote Code Execution vulnerability
This security update addresses a remote code execution vulnerability detailed in CVE-2026-70035.

CVE-2026-70174 - .NET Framework Remote Code Execution vulnerability
This security update addresses a remote code execution vulnerability detailed in CVE-2026-70174.

CVE-2026-83520 - .NET Framework Remote Code Execution vulnerability
This security update addresses a remote code execution vulnerability detailed in CVE-2026-83520.

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

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

CVE-2026-87697 - .NET Framework Remote Code Execution vulnerability
This security update addresses a remote code execution vulnerability detailed in CVE-2026-87697.

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

CVE-2026-96224 - .NET Framework Remote Code Execution vulnerability
This security update addresses a remote code execution vulnerability detailed in CVE-2026-96224.

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

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

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

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

CVE-2026-97788 - .NET Framework Information Disclosure vulnerability
This security update addresses an information disclosure vulnerability detailed in CVE-2026-97788.

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

CVE-2026-108398 - .NET Framework Mitigation Bypass vulnerability
This security update addresses a mitigation bypass vulnerability detailed in CVE-2026-108398.

Quality and Reliability Improvements

For a list of improvements that were released with this update, please see the article links in the Additional Information section of this article.

Known issues in this update

Microsoft is not currently aware of any issues in this update.

Additional information about this update

The following articles contain additional information about this update as it relates to individual product versions.

  • 5127666 Description of the Cumulative Update for .NET Framework 3.5 and 4.7.2 for Windows 10, version 1809 and Windows Server 2019 (KB5127666)
  • 5127685 Description of the Cumulative Update for .NET Framework 3.5 and 4.8 for Windows 10, version 1809 and Windows Server 2019 (KB5127685)

How to get this update

Release Channel Available Next Step
Windows Update and Microsoft Update Yes None. This update will be downloaded and installed automatically from Windows Update.
Windows Update for Business Yes None. This update will be downloaded and installed automatically from Windows Update.
Microsoft Update Catalog Yes To get the standalone package for this update, go to the Microsoft Update Catalog website.
Windows Server Update Services (WSUS) Yes This operating system update will offer, as applicable, and individual .NET Framework product updates will be installed. For more information about individual .NET Framework product updates see additional information about this update section.
This update will automatically sync with WSUS if you configure as follows:
Product: Windows 10, version 1809 and Windows Server 2019
Classification: Security Updates

How to obtain help and support for this update