The .NET team is taking steps that affect previously shipped .NET Framework releases and updates currently available for download from Microsoft. Some versions of .NET Frameworks detailed below will be unsupported and removed from the Microsoft Download Center. This does not impact customers taking the latest updates via Windows Update. They already have the latest .NET Framework 4.8 and no further action is necessary. See the following resources to learn more:
.NET Framework SHA-1 Retirement -- Impacted Products
.NET Framework SHA-1 Retirement Announcement
.NET Framework SHA-1 Retirement FAQs
.NET Framework Downloads
.NET Framework Application Compatibility
Runtime changes between .NET Framework 4.5.2 and .NET Framework 4.6.2
.NET Framework Migration Guide