.NET 8, .NET 9 and SQL Server 2016 end of support: what to do now
We review your systems, assess the risk and move them to .NET 10 and a supported SQL Server version, without stopping the business.
In short
Your systems keep running, but every new vulnerability found in them stays open. .NET 8 and .NET 9 get no security fixes from November 10, 2026, and extended support for SQL Server 2016 ended on July 14, 2026. The recommended path is a direct move to .NET 10, supported until November 2028. For SQL Server 2016 you can buy paid security updates (ESU) until July 2029 at the latest, as a temporary bridge rather than a solution.
What happened
- From November 10, 2026 Microsoft releases no security fixes for .NET 8 and .NET 9, including ASP.NET Core and Entity Framework Core. The next supported version is .NET 10, supported until November 2028.
- On July 14, 2026, extended support for SQL Server 2016 ended. Paid security updates (ESU) can be purchased until July 2029 at the latest.
The systems keep working. But every new vulnerability discovered in them stays open. In an organization subject to data security regulations, cyber insurance or a customer audit, this will come up at the very next audit.
What is supported, and until when
| Component | Status |
|---|
| .NET 8, .NET 9 | No security fixes from November 10, 2026 |
| .NET 10 | Supported until November 2028. This is a long-term support (LTS) release |
| .NET Framework 4.8.1 | Supported as a Windows component for as long as the Windows version itself is supported |
| SQL Server 2016 | Extended support ended on July 14, 2026. Paid ESU available until July 2029 at the latest |
What we do
- Inventory: every application, service and database, their versions and dependencies (libraries, drivers, third-party components).
- Risk assessment: what is urgent, what can wait, and where ESU costs less than migrating immediately.
- Plan: order of work, a downtime window if needed, and a rollback plan.
- Execution: upgrading the code to .NET 10, replacing unsupported libraries, migrating the database, and running performance tests before and after.
- After the migration: monitoring, documentation, and handover to your team.
What the initial review gives you
A short report: which components are already unsupported, the risk level of each, a scope estimate, and three options: full migration, phased migration, or ESU as a temporary bridge.
Why us
- Working with .NET and SQL Server since 2004.
- Our flagship system has been running in production since 2008.
- The architect handles the migration personally, it is not handed off.
Frequently asked questions
Will the system stop working on November 10, 2026?
No. It keeps working, but without security fixes.
Can we go straight from .NET 8 to .NET 10?
Yes, and that is the path Microsoft recommends.
How long does a migration take?
It depends on the number of systems and their dependencies. After the inventory we give an informed estimate, not a guess.
Our system runs on .NET Framework 4.8. Does this affect us?
Not directly. .NET Framework 4.8 and 4.8.1 are supported as Windows components. But if part of the system has already moved to .NET 8 or .NET 9, or if it works with SQL Server 2016, the review is relevant.
SLAtech LTD