At the .NET Conference 2021, Microsoft announced that .NET 5 will end support on May 8, 2022, while launching .NET 6. In an official blog post released yesterday, Microsoft once again urged .NET 5 users to upgrade to the new version as soon as possible, otherwise, service updates including security fixes and technical support will not be available.
Since .NET 5 is a non-LTS version, the support period is only 18 months, or 6 months after the new version is released, whichever is longer. Support for .NET 5.0 will end on May 8, 2022.
Apps that use .NET 5 will continue to work after .NET 5 ends support. That said, starting in May 2022, when Microsoft releases security updates for supported .NET versions (which will be .NET Core 3.1 and .NET 6.0), Microsoft will no longer release security updates for .NET 5.0.
This means that if a computer has .NET 5.0 installed, it may not be secure. Also, if you run into any issues and need technical support, Microsoft may not be able to help you.
If you are an end-user, Microsoft recommends contacting the vendor that manages your software to determine if an updated version of the software is required and available. The rest of this post is for software vendors and developers.
If your application uses .NET 5.0, Microsoft strongly recommends that you migrate your application to .NET 6.0 – a supported LTS version. You can download .NET 6.0 from the .NET website.