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 Update

    KB5046269

    SecUtility bypass and performance-counter disclosure addressed

    Addresses several .NET reliability problems, including a security feature-bypass issue and performance-counter information disclosure. It also addresses ASP.NET compilation, runtime, and user-group lookup problems.

    Check the newer update, KB5049615

    Key changes 7 changes

    • Fix ASP.NET: The System.Web.UI.Util initializer error during Visual Studio design-time compilation is addressed.
    • Fix CLR: In rare cases, a thread could get stuck in an endless loop the first time it entered the .NET runtime; this issue is addressed.
    • Fix CLR: When .NET optimizations are enabled, an interface call could be handled incorrectly; this issue is addressed.

    Read update Source: Microsoft

    Builds
    4.8.4770.0 · 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

    KB5046268

    Rare CLR loop and interface-call issues addressed

    Addresses several .NET Framework reliability issues, including a rare infinite loop when a thread first enters the CLR. It adds no new security improvements and includes previously released ones.

    Check the newer update, KB5049608

    Key changes 5 changes

    • Fix CLR: A rare issue that could cause an infinite loop when a thread first enters the Common Language Runtime is addressed.
    • Fix CLR: An issue with interface-call devirtualization is addressed in cases where JIT optimizations are enabled.
    • Fix CLR: An issue that could bypass a security feature when SecUtility.RandomByte is used is addressed.

    Read update Source: Microsoft

    Builds
    4.7.4121.0 · 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

    KB5045991

    Includes 1 improvement

    Includes cumulative quality and reliability improvements for .NET Framework 3.5, 4.8, and 4.8.1. It adds no new security improvements.

    Check the newer update, KB5048292

    Key changes 1 change

    • Improved .NET Framework: The update includes cumulative 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 Security update

    KB5044030

    Denial-of-service flaws and SQL CLR runtime exceptions addressed

    Addresses two .NET Framework denial-of-service vulnerabilities and issues that could cause SQL CLR runtime exceptions or prevent applications from targeting .NET Framework.

    Check the newer update, KB5049622

    Key changes 2 CVEs · 4 changes

    • Fix .NET Framework: Addresses a denial-of-service vulnerability in .NET Framework.
    • Fix .NET Framework: Addresses a denial-of-service vulnerability in .NET Framework.
    • Fix .NET Libraries: Addresses an issue that caused runtime errors in certain applications using SQL CLR.

    Read update Source: Microsoft

    Builds
    4.8.9277.0 · 2.0.50727.9179
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 21H2, 22H2 Security update

    KB5044029

    Runtime denial-of-service flaws and app targeting issue addressed

    The update addresses two .NET Framework denial-of-service vulnerabilities and reliability issues affecting SQL CLR scenarios and applications targeting .NET Framework.

    Check the newer update, KB5049621

    Key changes 2 CVEs · 2 changes

    • Fix .NET Libraries: Addresses runtime exceptions in certain SQL CLR-hosted scenarios following May cumulative updates.
    • Fix .NET Fundamentals: Addresses an issue that prevented applications from targeting .NET Framework.
    • Security CVE-2024-43483: .NET, .NET Framework, and Visual Studio Denial of Service Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.9277.0 · 2.0.50727.9179
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows Server 2022 Security update

    KB5044035

    Two denial-of-service flaws addressed; SQL CLR exceptions targeted

    Addresses two .NET Framework denial-of-service vulnerabilities and reliability issues involving SQL CLR hosted scenarios and applications targeting .NET Framework.

    Check the newer update, KB5049625

    Key changes 2 CVEs · 4 changes

    • Fix .NET Framework: A denial-of-service vulnerability in .NET Framework is addressed.
    • Fix .NET Framework: A second denial-of-service vulnerability in .NET Framework is addressed.
    • Fix .NET Libraries: Runtime exceptions in certain SQL CLR hosted scenarios after May cumulative updates are addressed.

    Read update Source: Microsoft

    Builds
    4.8.9277.0 · 2.0.50727.9179
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 21H2, 22H2 Security update

    KB5044020

    Two .NET denial-of-service flaws and SQL CLR exceptions addressed

    Addresses two .NET Framework denial-of-service vulnerabilities and runtime exceptions in certain SQL CLR hosted scenarios.

    Check the newer update, KB5049613

    Key changes 2 CVEs · 3 changes

    • Fix .NET Framework: Addresses a denial-of-service vulnerability in .NET Framework.
    • Fix .NET Framework: Addresses a denial-of-service vulnerability in .NET Framework.
    • Fix .NET Libraries: Addresses runtime exceptions in certain SQL CLR hosted scenarios after May cumulative updates.

    Read update Source: Microsoft

    Builds
    4.8.4762.0 · 2.0.50727.9179
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows Server 2022 Security update

    KB5044025

    Two service-stopping flaws and SQL app errors addressed

    The update addresses two .NET flaws that could stop services from responding. It also addresses errors in some .NET apps hosted by SQL Server.

    Check the newer update, KB5049617

    Key changes 2 CVEs · 3 changes

    • Fix .NET Framework: A .NET flaw that could make a service stop responding is addressed.
    • Fix .NET Framework: A .NET flaw that could make a service stop responding is addressed.
    • Fix .NET Libraries: Some .NET apps running inside SQL Server might show errors after May cumulative updates. The update addresses this issue.

    Read update Source: Microsoft

    Builds
    4.8.4762.0 · 2.0.50727.9179
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 1809 · Windows Server 2019 Security update

    KB5044022

    .NET denial-of-service flaws and SQL CLR exceptions addressed

    The update addresses two .NET Framework denial-of-service vulnerabilities and runtime exceptions in certain SQL CLR hosted scenarios.

    Check the newer update, KB5049615

    Key changes 2 CVEs · 3 changes

    • Fix .NET Framework: Addresses a denial-of-service vulnerability in .NET Framework.
    • Fix .NET Framework: Addresses a denial-of-service vulnerability in .NET Framework.
    • Fix .NET Libraries: Addresses runtime exceptions in certain SQL CLR hosted scenarios caused by May cumulative updates.

    Read update Source: Microsoft

    Builds
    4.8.4762.0 · 2.0.50727.9066
    Security
    2 vulnerabilities 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

    KB5044016

    Framework denial-of-service flaws addressed

    The update addresses two .NET Framework denial-of-service vulnerabilities, CVE-2024-43483 and CVE-2024-43484. A restart is required if affected files are in use.

    Check the newer update, KB5049608

    Key changes 2 CVEs · 2 changes

    • Improved .NET Framework: The update addresses a .NET Framework denial-of-service vulnerability identified as CVE-2024-43483.
    • Improved .NET Framework: The update addresses a .NET Framework denial-of-service vulnerability identified as CVE-2024-43484.
    • Security CVE-2024-43483: .NET, .NET Framework, and Visual Studio Denial of Service Vulnerability

    Read update Source: Microsoft

    Builds
    4.7.4115.0 · 2.0.50727.9066
    Security
    2 vulnerabilities fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 21H2, 22H2 Update

    KB5042097

    ASP.NET compilation conflicts and UI automation rendering addressed

    Addresses .NET Framework reliability issues, including UI automation rendering and compilation conflicts that could slow work on large projects.

    Check the newer update, KB5044029

    Key changes 5 changes

    • Fix .NET Libraries: The update addresses an issue with bringing the zlib file up to its latest version.
    • Fix .NET Fundamentals: The update addresses a problem rendering ListView subitems used by UI automation.
    • Fix .NET Fundamentals: The update addresses an issue involving a serialization binder bypass through BinaryFormatter mutations.

    Read update Source: Microsoft

    Builds
    4.8.9261.0 · 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

    KB5041964

    Fixes ListView rendering and ASP.NET project slowdowns

    Addresses reliability issues in .NET Framework, including ListView rendering and slowdowns in some large ASP.NET projects. It includes previously released security improvements but no new ones.

    Check the newer update, KB5044035

    Key changes 5 changes

    • Improved .NET Libraries: The update replaces a zlib file with the latest version.
    • Fix .NET Fundamentals: Automated tools can render the smaller entries inside a list view.
    • Fix .NET Fundamentals: The update addresses a case where modifying binary-formatted data could bypass a check before the data was read.

    Read update Source: Microsoft

    Builds
    4.8.9266.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 21H2, 22H2 Update

    KB5042056

    Visual Studio build conflicts and WebForms metadata issues addressed

    Addresses .NET reliability issues involving zlib, UI automation, serialization, ASP.NET WebForms, and Visual Studio compilation. It adds no new security improvements.

    Check the newer update, KB5044020

    Key changes 5 changes

    • Fix .NET Libraries: The update addresses an issue with updating the zlib file to its latest version.
    • Fix .NET Fundamentals: The update addresses an issue affecting the rendering of UI automation ListView sub-items.
    • Fix .NET Fundamentals: The update addresses an issue where BinaryFormatter mutations could bypass the serialization binder.

    Read update Source: Microsoft

    Builds
    4.8.4744.0 · 2.0.50727.9179
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows Server 2022 Update

    KB5041948

    UI automation and large ASP.NET project slowdowns addressed

    Addresses .NET reliability issues, including ListView rendering and conflicts that could slow large ASP.NET projects in Visual Studio. It adds no new security improvements.

    Check the newer update, KB5044025

    Key changes 5 changes

    • Fix .NET Libraries: The zlib file is updated to the latest version.
    • Fix .NET Fundamentals: An issue rendering ListView subitems in UI automation is addressed.
    • Fix .NET Fundamentals: An issue involving serialization binder bypasses with BinaryFormatter mutations is addressed.

    Read update Source: Microsoft

    Builds
    4.8.4749.0 · 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

    KB5041974

    Zlib, ListView rendering and ASP.NET issues addressed

    Addresses reliability issues in zlib, UI automation, ASP.NET and Visual Studio interactions. It includes previously released security improvements but no new ones.

    Check the newer update, KB5044022

    Key changes 5 changes

    • Fix .NET Libraries: An issue with the zlib file is addressed by updating it to the latest version.
    • Fix .NET Fundamentals: An issue involving the rendering of UI automation ListView subitems is addressed.
    • Fix .NET Fundamentals: An issue involving binary formatter mutations that bypass the serialization binder is addressed.

    Read update Source: Microsoft

    Builds
    4.8.4749.0 · 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

    KB5041913

    Updates zlib and corrects .NET data handling and WebForms metadata

    The update refreshes a .NET library file and addresses two .NET issues, including unwanted metadata on some generated web pages. It contains no new security improvements.

    Check the newer update, KB5044016

    Key changes 3 changes

    • Fix .NET Libraries: A file used by .NET libraries is updated to its latest version.
    • Fix .NET Fundamentals: A .NET issue involving a bypass in handling serialized data is addressed.
    • Fix .NET Fundamentals: An affected web-page feature no longer adds certain advisory and content-rating information to pages.

    Read update Source: Microsoft

    Builds
    4.7.4108.0 · 2.0.50727.9066
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows 10 22H2 Optional preview
    Preview

    KB5041168

    ListView rendering, zlib, and ASP.NET issues addressed

    Addresses several .NET Framework reliability issues, including ListView rendering, serialization, and ASP.NET project compilation problems.

    Key changes 5 changes

    • Fix .NET Libraries: The update addresses an issue with bringing the zlib file up to its latest version.
    • Fix .NET Fundamentals: The update addresses a problem that could prevent UI automation from rendering ListView subitems.
    • Fix .NET Fundamentals: The update addresses an issue where binary formatter mutations could bypass the serialization binder.

    Read update Source: Microsoft

    Builds
    4.8.9261.0 · 2.0.50727.9177
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 22H2 Optional preview
    Preview

    KB5041167

    Fixes .NET list rendering and ASP.NET project slowdowns

    Addresses .NET issues involving automated list rendering, data safety checks, ASP.NET page metadata, and slowdowns in large projects using Visual Studio.

    Key changes 5 changes

    • Fix .NET Libraries: A component used to compress data is updated to the latest zlib version.
    • Fix .NET Fundamentals: Sub-items in automated interface lists can now render properly.
    • Fix .NET Fundamentals: The update addresses a case where modified data could get around a .NET safety check.

    Read update Source: Microsoft

    Builds
    4.8.4744.0 · 2.0.50727.9177
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 22H2 Optional preview
    Preview

    KB5041355

    Reliability changes for framework versions 3.5, 4.8 and 4.8.1

    Includes quality and reliability improvements for .NET Framework 3.5, 4.8 and 4.8.1 on Windows 10, version 22H2. It adds no new security improvements.

    Key changes 1 change

    • Improved .NET Framework: The update 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 10 21H2, 22H2 Security update

    KB5039893

    Elevation flaw fixed; temporary-path behavior changes

    CVE-2024-38081 is addressed. On Windows versions that expose `GetTempPath2`, `System.IO.Path.GetTempPath` can return a different path for SYSTEM processes, so affected software may need changes.

    Check the newer update, KB5044029

    Key changes 1 CVE · 3 changes

    • Fix .NET Framework: The update addresses an elevation-of-privilege vulnerability.
    • Fix WinForms: Addresses an issue with memory leaks associated with objects held in memory.
    • Fix .NET Fundamentals: Addresses an issue using X.509 certificates under PPL in Azure AD.

    Read update Source: Microsoft

    Builds
    4.8.9256.0 · 2.0.50727.9177
    Security
    1 vulnerability fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8.1 .NET Framework 3.5 / 4.8.1 for Windows Server 2022 Security update

    KB5039907

    Temporary-path behavior changes alongside a privilege fix

    The update fixes an elevation-of-privilege vulnerability in .NET Framework and changes the temporary path returned by System.IO.Path.GetTempPath, which might require affected applications to adapt.

    Check the newer update, KB5044035

    Key changes 1 CVE · 4 changes

    • Improved System.IO.Path.GetTempPath: Some applications might get a different temporary-folder path. Affected software is expected to change its code to adapt.
    • Fix .NET Framework: An elevation-of-privilege vulnerability in .NET Framework is addressed.
    • Fix Winforms: An issue with memory leaks involving AccessibleObjects held in memory is addressed.

    Read update Source: Microsoft

    Builds
    4.8.9256.0 · 2.0.50727.9177
    Security
    1 vulnerability fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 21H2, 22H2 Security update

    KB5039884

    Addresses elevation flaw; temp paths change where GetTempPath2 exists

    The update addresses CVE-2024-38081 and a WinForms memory-leak issue. On Windows versions that expose the GetTempPath2 API, System.IO.Path.GetTempPath uses that API and returns its resolved path.

    Check the newer update, KB5044020

    Key changes 1 CVE · 3 changes

    • Improved System.IO.Path.GetTempPath: On Windows versions that expose GetTempPath2, apps using System.IO.Path.GetTempPath receive the path resolved by that API. For SYSTEM p...
    • Fix .NET Framework: The update addresses a security vulnerability in .NET Framework.
    • Fix Winforms: Memory leaks linked to WinForms accessibility objects are addressed.

    Read update Source: Microsoft

    Builds
    4.8.4739.0 · 2.0.50727.9177
    Security
    1 vulnerability fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows Server 2022 Security update

    KB5039889

    WinForms memory leaks reduced; privilege escalation addressed

    Addresses an elevation-of-privilege vulnerability and reduces WinForms memory leaks. The security fix also changes temporary-path results for SYSTEM processes on Windows versions that expose GetTempPath2.

    Check the newer update, KB5044025

    Key changes 1 CVE · 2 changes

    • Fix .NET Framework: An elevation-of-privilege vulnerability is addressed.
    • Fix WinForms: Memory leaks associated with AccessibleObjects held in memory are reduced.
    • Security CVE-2024-38081: .NET, .NET Framework, and Visual Studio Elevation of Privilege Vulnerability

    Read update Source: Microsoft

    Builds
    4.8.4739.0 · 2.0.50727.9177
    Security
    1 vulnerability fixed
    Restart
    Required
  • .NET Framework 3.5 / 4.8 .NET Framework 3.5 / 4.8 for Windows 10 1809 · Windows Server 2019 Security update

    KB5039886

    Temporary-folder paths change; WinForms memory leaks addressed

    The update addresses CVE-2024-38081, which the page describes as a remote code execution vulnerability, and changes how .NET gets temporary-folder paths on some Windows versions.

    Check the newer update, KB5044022

    Key changes 1 CVE · 3 changes

    • Improved System.IO.Path.GetTempPath: Some applications may get a different temporary-folder path after the security fix. Affected software is expected to adapt to the new b...
    • Fix .NET Framework: The update addresses CVE-2024-38081, a security vulnerability in .NET Framework.
    • Fix Winforms: The size of memory leaks involving WinForms accessibility objects held in memory is addressed.

    Read update Source: Microsoft

    Builds
    4.8.4739.0 · 2.0.50727.9064
    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

    KB5039879

    Temp-path behavior changes to close a privilege flaw

    The update addresses CVE-2024-38081, an elevation-of-privilege vulnerability. It also changes how .NET resolves temporary paths, which may require affected applications to adapt.

    Check the newer update, KB5044016

    Key changes 1 CVE · 2 changes

    • Fix .NET Framework: Addresses an elevation-of-privilege vulnerability.
    • Fix Winforms: Addresses a memory leak associated with AccessibleObjects held in memory.
    • Security CVE-2024-38081: .NET, .NET Framework, and Visual Studio Elevation of Privilege Vulnerability

    Read update Source: Microsoft

    Builds
    4.7.4101.0 · 2.0.50727.9064
    Security
    1 vulnerability fixed
    Restart
    Required