Microsoft’s ASP.NET Core 2.3, a version of the company’s open source web development framework for .NET and C#, will reach end of life support on April 7, 2027.

Following that date, Microsoft will no longer provide bug fixes, technical support, or security patches for ASP.NET Core 2.3, the company announced on April 7, exactly a year before the cessation date. ASP.NET Core 2.3 packages—the latest patched versions only—are supported currently on .NET Framework, following the support cycle for those .NET Framework versions. After April 7, 2027, this support will end regardless of the .NET Framework version in use, according to Microsoft. Support for ASP.NET Core 2.3 packages including the Entity Framework 2.3 packages will end on the same date.

Microsoft recommends upgrading to a currently supported version of .NET, such as .NET 10 LTS. To help with the upgrade process, Microsoft recommends using GitHub Copilot modernization, which provides AI-powered assistance in planning and executing migrations to a modern .NET version.

Microsoft detailed the release of ASP.NET 2.3 in February 2025. The company lists the following impacts as a result of its end of support:

• Applications will continue run; end of support does not break existing applications.
• No new security updates will be issued for ASP.NET Core 2.3.
• Continuing to use an unsupported version may expose applications to security vulnerabilities.
• Technical support will no longer be available for ASP.NET Core 2.3.
• The ASP.NET Core 2.3 packages will be deprecated.

ASP.NET Core is the open-source version of ASP.NET that runs on macOS, Linux, and Windows. ASP.NET Core first was released in 2016 and is a re-design of earlier Windows-only versions of ASP.NET.