Skip to the content
The Update Bureau

.NET Framework 3.5

.NET Framework 3.5

Every published release for .NET Framework 3.5, newest first: what each update changes, whether to install it and any confirmed known issues.

Latest
KB5127694 Oct 13, 2026
File version
2.0.50727.9188
Released
Nov 19, 2007
All editions
updates until Jan 9, 2029
Known issues
1 open

Update history

  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 1809 · Windows Server 2019 Security update

    KB5066137

    Information disclosure flaw in .NET runtime addressed

    The update addresses an information disclosure vulnerability in .NET Framework 3.5 and 4.8 on Windows 10, version 1809 and Windows Server 2019. A restart might be needed if affected files are in use.

    Check the newer update, KB5082414

    Key changes 1 CVE · 1 change

    • Fix .NET Framework: An information disclosure vulnerability in .NET Framework is addressed.
    • Security CVE-2025-55248: .NET, .NET Framework, and Visual Studio Information Disclosure Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.4798.0 · 2.0.50727.9067
    Security
    1 vulnerability fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.7.2 .NET Framework 3.5 / 4.7.2 for Windows 10 1809 · Windows Server 2019 Security update

    KB5066143

    Information disclosure flaw in framework components addressed

    The update addresses CVE-2025-55248, an information disclosure vulnerability in .NET Framework. A restart is required if affected files are in use.

    Check the newer update, KB5082413

    Key changes 1 CVE · 1 change

    • Fix .NET Framework: An information disclosure vulnerability is addressed.
    • Security CVE-2025-55248: .NET, .NET Framework, and Visual Studio Information Disclosure Vulnerability

    Read update Source: Microsoft

    Builds
    4.7.4137.0 · 2.0.50727.9067
    Security
    1 vulnerability fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 24H2 · Windows Server 2025 Optional preview
    Preview

    KB5064401

    ASP.NET event logging fixed; WPF certificate update addressed

    Addresses missing ASP.NET error events in the Windows Event log and a WPF GB18030 certificate update. You must restart after installation if affected files are in use.

    Check the newer update, KB5066131

    Key changes 2 changes

    • Fix ASP.NET: Some ASP.NET error events are logged properly in the Windows Event log.
    • Fix WPF: The WPF update for the GB18030 certificate related to Chinese language changes is addressed.

    Read update Source: Microsoft

    Builds
    4.8.9316.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 23H2 Optional preview
    Preview

    KB5064403

    ASP.NET event logging and GB18030 certificate handling updated

    The update addresses ASP.NET error events that might not be logged properly and a WPF update for the GB18030 certificate used in Chinese language changes.

    Check the newer update, KB5066133

    Key changes 2 changes

    • Improved WPF: Includes an update for the GB18030 certificate for Chinese language changes.
    • Fix ASP.NET: Some ASP.NET error events are logged properly in the Windows Event log.

    Read update Source: Microsoft

    Builds
    4.8.9316.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 21H2, 22H2 Optional preview
    Preview

    KB5064400

    ASP.NET event logging fixed; GB18030 certificate updated

    The update addresses ASP.NET event logging and a GB18030 certificate update for Chinese-language changes. If you already installed the August 26 release, you do not need to take action.

    Check the newer update, KB5066130

    Key changes 2 changes

    • Improved WPF: The GB18030 certificate receives an update related to Chinese-language changes.
    • Fix ASP.NET: Some ASP.NET error events that failed to appear in the Windows Event log are addressed.

    Read update Source: Microsoft

    Builds
    4.8.9316.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows Server 2022 Update

    KB5065753

    ASP.NET event logging issue addressed

    The update addresses ASP.NET error events that might not be logged properly and an update related to the GB18030 certificate for Chinese-language changes.

    Check the newer update, KB5066134

    Key changes 2 changes

    • Improved WPF: Addresses an update for the GB18030 certificate for Chinese-language changes.
    • Fix ASP.NET: Some ASP.NET error events are logged properly in the Windows Event log.

    Read update Source: Microsoft

    Builds
    4.8.9318.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 21H2, 22H2 Optional preview
    Preview

    KB5064399

    ASP.NET event logging issue addressed; WPF certificate change

    Some ASP.NET error events that failed to log properly in Windows Event log are addressed. The update also includes a WPF change related to the GB18030 certificate for Chinese-language changes.

    Check the newer update, KB5066135

    Key changes 2 changes

    • Improved WPF: WPF receives a change related to the GB18030 certificate for Chinese-language changes.
    • Fix ASP.NET: Some ASP.NET error events that failed to log properly in Windows Event log are addressed.

    Read update Source: Microsoft

    Builds
    4.8.4796.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows Server 2022 Update

    KB5065748

    ASP.NET logging issue addressed; Chinese WPF certificate updated

    Addresses an issue where some ASP.NET error events fail to log and updates a certificate for Chinese language changes in WPF.

    Check the newer update, KB5066139

    Key changes 2 changes

    • Improved WPF: A GB18030 certificate is updated for Chinese language changes in WPF.
    • Fix ASP.NET: Addresses an issue where some ASP.NET error events fail to appear in the Windows Event log.

    Read update Source: Microsoft

    Builds
    4.8.4797.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 1809 · Windows Server 2019 Update

    KB5065755

    ASP.NET error logging improved; GB18030 certificate updated

    The update addresses ASP.NET error events that fail to log properly and a WPF update for the GB18030 certificate and Chinese language changes. It includes no new security improvements.

    Check the newer update, KB5066137

    Key changes 2 changes

    • Improved WPF: The GB18030 certificate update for Chinese language changes is addressed.
    • Fix ASP.NET: Some ASP.NET error events that fail to log properly in the Windows Event log are addressed.

    Read update Source: Microsoft

    Builds
    4.8.4797.0 · 2.0.50727.9066
    Restart
    Required
  • .NET Framework 3.5 / 4.7.2 .NET Framework 3.5 / 4.7.2 for Windows 10 1809 · Windows Server 2019 Update

    KB5065744

    ASP.NET event logging and GB18030 certificate updated

    The update addresses an ASP.NET problem that prevented some error events from being logged and updates a certificate for Chinese language changes. It includes no new security improvements.

    Check the newer update, KB5066143

    Key changes 2 changes

    • Improved WPF: The GB18030 certificate is updated for Chinese language changes.
    • Fix ASP.NET: The update addresses a problem that caused some ASP.NET error events to fail to appear in the Windows Event log.

    Read update Source: Microsoft

    Builds
    4.7.4136.0 · 2.0.50727.9066
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 22H2 Optional preview
    Preview

    KB5064794

    Cumulative quality updates for .NET runtime components

    Includes quality and reliability improvements for .NET Framework 3.5, 4.8 and 4.8.1. Windows Update downloads and installs it automatically; a restart might be requested.

    Key changes 1 change

    • Improved .NET Framework: Includes quality and reliability improvements for .NET Framework 3.5, 4.8 and 4.8.1.

    Read update Source: Microsoft

    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 24H2 · Windows Server 2025 Optional preview
    Preview

    KB5056579

    Type-converter concurrency and runtime error dialogs addressed

    Addresses .NET type-converter concurrency problems and error-reporting dialogs linked to DLL loading and OS code integrity checks. It adds no new security improvements; devices that already installed it need no action.

    Check the newer update, KB5064401

    Key changes 2 changes

    • Fix .NET Libraries: A concurrency issue involving .NET type-converter lookups is addressed.
    • Fix .NET Runtime: An issue that can trigger error-reporting dialog boxes during .NET Framework DLL loading and OS code integrity checks is addressed.

    Read update Source: Microsoft

    Builds
    4.8.9310.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 23H2 Update

    KB5056580

    Type conversion and .NET load error dialogs addressed

    .NET type conversion concurrency and error dialogs from some library loads are addressed. The Windows 11 22H2 package is now available through WSUS and the Update Catalog.

    Check the newer update, KB5064403
    Known issues: 1 open Organizations and IT administrators
    • The Windows 11, version 22H2 package KB5056580 was not available on Windows Server Update Services (WSUS) or Microsoft Update Catalog.

    Key changes 2 changes

    • Improved .NET Libraries: The update addresses a concurrency problem that can affect type conversion in .NET apps.
    • Improved .NET Runtime: The update addresses error dialogs that can appear when some .NET libraries load.

    Read update Source: Microsoft

    Builds
    4.8.9310.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 21H2, 22H2 Optional preview
    Preview

    KB5056578

    Addresses type-converter concurrency and runtime error dialogs

    The update addresses a .NET type-conversion concurrency issue and error dialogs triggered by .NET DLL loads under OS code integrity enforcement. If you installed it previously, the July release requires no action.

    Check the newer update, KB5064400

    Key changes 2 changes

    • Fix .NET Libraries: Addresses a concurrency issue affecting .NET type conversion and property lookup.
    • Fix .NET Runtime: Addresses error dialogs that can appear when .NET Framework DLLs load under the operating system’s code integrity policy.

    Read update Source: Microsoft

    Builds
    4.8.9310.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows Server 2022 Update

    KB5062061

    TypeDescriptor concurrency and .NET error dialogs addressed

    Addresses a .NET TypeDescriptor concurrency issue and error-reporting dialogs triggered by interactions with Windows code integrity enforcement. It includes no new security improvements.

    Check the newer update, KB5065753

    Key changes 2 changes

    • Improved .NET Libraries: Addresses a concurrency issue involving .NET property and type-converter lookup.
    • Improved .NET Runtime: Addresses error-reporting dialog boxes triggered by interactions between .NET Framework DLL loads and Windows code integrity enforcemen...

    Read update Source: Microsoft

    Builds
    4.8.9315.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 21H2, 22H2 Optional preview
    Preview

    KB5056577

    TypeDescriptor concurrency and .NET error dialogs addressed

    The update addresses two .NET reliability issues: concurrency in TypeDescriptor calls and error dialogs during DLL loads. The July 8 release is unchanged from April 22; if you already installed it, no action is needed.

    Check the newer update, KB5064399

    Key changes 2 changes

    • Fix .NET Libraries: A concurrency issue involving .NET type properties and converters is addressed.
    • Fix .NET Runtime: Error-reporting dialog boxes caused by interactions between .NET Framework DLL loads and OS code integrity enforcement are addressed.

    Read update Source: Microsoft

    Builds
    4.8.4790.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows Server 2022 Update

    KB5062063

    TypeDescriptor concurrency and DLL error-dialog issues addressed

    Addresses two .NET reliability issues involving TypeDescriptor and DLL loading. It includes previously released security improvements but adds none.

    Check the newer update, KB5065748

    Key changes 2 changes

    • Fix .NET Libraries: A concurrency issue affecting .NET type-property and converter lookups is addressed.
    • Fix .NET Runtime: An issue that can trigger error-reporting dialog boxes during .NET Framework DLL loading is addressed.

    Read update Source: Microsoft

    Builds
    4.8.4795.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 1809 · Windows Server 2019 Update

    KB5062068

    TypeDescriptor concurrency and .NET error dialogs addressed

    The update addresses a .NET concurrency issue and error-reporting dialogs triggered by interactions between .NET Framework DLL loads and Windows code integrity enforcement.

    Check the newer update, KB5065755

    Key changes 2 changes

    • Fix .NET Libraries: A concurrency issue involving .NET property and type information is addressed.
    • Fix .NET Runtime: Error-reporting dialog boxes caused by interactions between .NET Framework DLL loads and Windows code integrity enforcement are address...

    Read update Source: Microsoft

    Builds
    4.8.4795.0 · 2.0.50727.9066
    Restart
    Required
  • .NET Framework 3.5 / 4.7.2 .NET Framework 3.5 / 4.7.2 for Windows 10 1809 · Windows Server 2019 Update

    KB5062070

    .NET library timing issues and error dialogs addressed

    Addresses a timing issue in .NET library functions and error-reporting dialogs that could appear while .NET libraries load.

    Check the newer update, KB5065744

    Key changes 2 changes

    • Fix .NET Libraries: Some .NET applications that inspect object properties work more reliably when several operations happen at once.
    • Fix .NET Runtime: Applications might no longer show error-reporting dialogs when .NET loads a library while Windows checks whether its code is trusted.

    Read update Source: Microsoft

    Builds
    4.7.4135.0 · 2.0.50727.9066
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 22H2 Optional preview
    Preview

    KB5057056

    Includes 2 improvements

    Includes previously released security improvements and quality and reliability changes for Windows 10 version 22H2. It adds no new security improvements.

    Check the newer update, KB5064794

    Key changes 2 changes

    • Improved .NET Framework: Previously released security improvements remain included in this cumulative update.
    • Improved .NET Framework: The update includes quality and reliability improvements.

    Read update Source: Microsoft

    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 11 24H2 · Windows Server 2025 Optional preview
    Preview

    KB5054979

    UNC file and directory operations get a reliability fix

    Addresses an issue with .NET file and directory operations on UNC shares. It contains no new security improvements.

    Check the newer update, KB5056579

    Key changes 1 change

    • Fix .NET Fundamentals: Addresses an issue with file and directory operations on network shares.

    Read update Source: Microsoft

    Builds
    4.8.9300.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 21H2, 22H2 Optional preview
    Preview

    KB5054978

    Network-share file operations get a reliability fix

    The update addresses an issue with .NET applications that use file and directory APIs on network shares. If you already installed the April 8, 2025 Security and Quality Rollup, no action is needed.

    Check the newer update, KB5056578

    Key changes 1 change

    • Fix .NET Fundamentals: Addresses an issue with .NET applications that use file and directory APIs on network shares.

    Read update Source: Microsoft

    Builds
    4.8.9300.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows Server 2022 Update

    KB5054693

    WPF printing memory errors and UNC file access addressed

    The update addresses a WPF printing issue involving large numbers of pages and a .NET file and directory API issue on UNC shares. A restart might be needed if affected files are in use.

    Check the newer update, KB5062061

    Key changes 2 changes

    • Fix WPF: The update addresses memory errors that can interrupt printing large numbers of pages in WPF apps.
    • Fix .NET Fundamentals: The update addresses an issue affecting apps that use file and directory APIs on UNC shares.

    Read update Source: Microsoft

    Builds
    4.8.9305.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 21H2, 22H2 Optional preview
    Preview

    KB5054977

    File operations on network shares are addressed

    The update addresses a .NET issue involving files and folders on network shares. It adds no new security improvements.

    Check the newer update, KB5056577

    Key changes 1 change

    • Fix .NET Fundamentals: The update addresses a problem when .NET applications work with files and folders on network shares.

    Read update Source: Microsoft

    Builds
    4.8.4780.0 · 2.0.50727.9179
    Restart
    Required