Microsoft has announced that ASP.NET Core 2.3 will reach the end of its support period on April 7, 2027. From that point on, the company will completely stop providing security updates, bug fixes, and technical support for this version of the framework.
The announcement follows Microsoft’s standard lifecycle guidelines, which require developers to be notified at least twelve months in advance of the discontinuation of support for tools. ASP.NET Core 2.3 falls under this category and will therefore have a limited transition period.
Currently, ASP.NET Core 2.3 is still supported alongside the .NET Framework, as long as the .NET Framework version used is within its support period. However, that link will expire completely after April 2027, regardless of the underlying version. It is noteworthy that .NET Framework itself will continue to be supported as part of Windows, which makes the end of ASP.NET Core 2.3 all the more of a deliberate choice.
Moreover, the background of this version is less straightforward than the name suggests. ASP.NET Core 2.3 is actually a re-release of version 2.1, intended to resolve previous compatibility issues. In doing so, Microsoft deviated from standard versioning practices, which caused confusion and frustration among some developers.
From a functional standpoint, little will change for organizations on the end-of-life date itself. Applications will continue to run as usual, but will no longer receive security updates after that date. This increases the risk of vulnerabilities, while Microsoft’s support also ceases. Additionally, the relevant packages will be officially marked as deprecated.
Legacy maintenance weighs heavily on Microsoft
According to reports by The Register, broader strategic considerations are also at play. Microsoft reportedly views maintaining older versions as costly, preferring to allocate resources to the continued development of modern .NET versions. At the same time, the company emphasizes that support for ASP.NET Core on the .NET Framework was always intended as a temporary migration step.
This positioning is a sensitive issue. Some users perceive the decision as an abrupt change of course, partly because version 2.3 was introduced specifically to mitigate migration issues. However, by classifying it as a “tool,” Microsoft can get by with a relatively short 12-month notice period, according to The Register.
Microsoft emphasizes that migrating to a newer version of .NET is the best route. According to the company, modern versions offer clear improvements in performance, security, and development productivity. Among the recommended targets, it mentions .NET 10, a long-term support release that is also cross-platform.