.NET 8 and .NET 9 lose support as Microsoft ships .NET 11

.NET 8 and .NET 9 lose support as Microsoft ships .NET 11

10 November 2026: Microsoft's .NET 8 and .NET 9 have reached the end of support on the day .NET 11 was released. Versions 8.0.34 and 9.0.23, published alongside it, are the last patches either line will receive, so any flaw found from now on in those runtimes stays unfixed.

Two lines end on the same day

The two versions arrived a year apart but leave together. .NET 8, released on 14 November 2023, was a long-term support release with three years of fixes. .NET 9, released on 12 November 2024, was a standard-term release whose support ended on the same date. Microsoft's support table now lists both under out-of-support versions.

The practical effect lands on applications, not just developer machines: web services, background workers and desktop apps built on either version, and container images that bundle the runtime, stop getting security fixes. Microsoft shipped an out-of-band security release for 8.0, 9.0 and 10.0 only weeks ago, which shows how often those fixes come.

Where to move

Version	Type	Released	Support ends
.NET 11	Standard term	10 November 2026	14 November 2028
.NET 10	Long term	11 November 2025	14 November 2028
.NET 9	Standard term	12 November 2024	Ended 10 November 2026
.NET 8	Long term	14 November 2023	Ended 10 November 2026

.NET 10, the current long-term release, had its own patch, 10.0.15, on 10 November. Microsoft's announcement says .NET 10 remains the supported long-term option, which makes it the conservative target for teams leaving .NET 8. The new .NET 11 has the same end date, 14 November 2028, because the standard-term period is now two years.

What .NET 11 adds

Microsoft's release post names union types and closed hierarchies in C

15, a Native AOT host for the command-line tooling, and OpenAPI 3.2 support in ASP.NET Core. .NET Conf runs from 10 to 13 November with the release sessions.

For teams still on .NET 8, the jump to .NET 10 is two major versions, which usually means checking breaking-change lists for both 9 and 10 rather than one. Teams that bought .NET applications from a vendor should ask which runtime the product ships on and when the vendor's own move is scheduled, since an unsupported runtime inside a supported product is still unpatched.

Sources

• Microsoft: .NET and .NET Core official support policy, support dates table (read 10 November 2026), 10 November 2026
• Microsoft .NET Blog: Announcing .NET 11, 10 November 2026, 10 November 2026