.NET Framework covers a broad set of Windows technologies including the .NET Framework Base Class Libraries, ASP.NET Web Forms, WCF, and more.
Many products both within and outside Microsoft rely on .NET Framework. Beginning with version 4.5.2 and later, .NET Framework is defined as a component of the Windows operating system (OS). Components receive the same support as their parent products, therefore, .NET Framework 4.5.2 and later follows the lifecycle policy of the underlying Windows OS on which it is installed. The support lifecycle for various versions of Windows can be found on the Windows lifecycle fact sheet.
.NET Framework 4.8 is the latest version of .NET Framework and will continue to be distributed with future releases of Windows. As long as it is installed on a supported version of Windows, .NET Framework 4.8 will continue to also be supported.
The Support Lifecycle information for all versions of .NET Framework can be seen on the Microsoft Product Lifecycle site. ASP.NET ships external components separate from the .NET Framework. Please see ASP.NET support policy for the available options.
.NET Framework content previously digitally signed using certificates that use the SHA-1 algorithm will be retired in order to support evolving industry standards.
The .NET Framework versions 4.5.2, 4.6, and 4.6.1 will reach end of support on April 26, 2022. After this date, security fixes, updates, and technical support for these versions will no longer be provided.
Update your deployed runtime to a more recent version, such as .NET Framework 4.6.2 before April 26, 2022 in order to continue to receive updates and technical support.
For more information, see the SHA-1 retirement plan, the .NET Framework 4.5.2, 4.6, and 4.6.1 lifecycle update blog post, and the FAQ.