KB5015732 .NET Framework update 3.5, 4.8 for Windows 11

KB5015732 is basically a .NET Framework cumulative update for Windows 11 that brings reliability improvements to WPF and Networking. Though this is not a security update, we suggest applying this patch update to your computer. 

This update has one prerequisite and that is – “You must have .NET Framework 3.5 or 4.8 installed on your Windows PC”. Do restart your computer after you upgrade your device to this patch update. 

.NET Framework update - KB5015732

KB5015732 Summary

There are no new security improvements in this release. This patch is just a cumulative update and contains the security updates of the previous releases. 

Quality and reliability improvements

Windows Presentation Foundation:

  • Works upon an issue where invoking a synchronization Wait on the UI thread can lead to a render-thread failure, due to unexpected re-entrancy.


  • Addresses an issue that causes Ssl negotiation to hang indefinitely while using client certificates during TLS 1.3 negotiation. This also causes PostHandshakeAuthentiction to fail with SslStream or HttpWebRequest getting into a timeout. One must disable TLS 1.3 either via Switch.System.Net.DontEnableTls13 AppContext or OS registry to resolve this problem. This problem now stands resolved as per Microsoft. 

Known Issues on this NET Framework update for Windows 11

So far, we are not aware of any known issues on this patch update. 

How to download and install KB5015732 on Windows 11?

By default, you will receive a prompt stating that – “KB5015732 has been downloaded, restart your PC to install it on your computer”. In case this update is missing on Windows Update, you may get this manually as well. To do so, visit Microsoft’s update catalog and type KB5015732 in the search bar. Press Enter to view the available updates matching this KB number. 


Pick the update that best matches your system architecture and hit the Download button available next to it. Moving forward, click on the link that appears in the pop-up window. The downloading process will start immediately afterward and will download the setup file in the “.msu” file format. 

KB5015732 - x64 download

When the download completes, double-click on it to begin its installation. Your system might restart after this patch update is installed successfully. 

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