GalaxyTechnology
Self-check · October 2026

.NET 8 upgrade readiness check: is your application ready for .NET 10?

.NET 8 and .NET 9 lose security support on 10 November 2026, 38 days from today. Answer ten questions about your application to see how ready it is for .NET 10 and where the risks are.

Answer for the application your business depends on most. If you're not sure of an answer, choose "Don't know": that's useful information in itself. Your answers stay in your browser. Nothing is sent or stored.

1. Which .NET version does the application run on?
2. Does it handle personal data, card payments or customer logins?
3. Do you need Cyber Essentials or ISO 27001, or answer customers' security questionnaires?
4. How many applications, services and scheduled jobs make up the system?
5. Is the source code in a repository your business controls, and can it be built from scratch?
6. Are the main business processes covered by automated tests?
7. Are the third-party (NuGet) packages it uses kept up to date?
8. Where does it run?
9. Is releasing a new version a repeatable, documented process?
10. Is the developer who built or looks after it still available to you?

What the questions are looking for

  • Exposure: how much harm an unpatched vulnerability could do (questions 1–3).
  • Size: how much there is to upgrade and test (questions 4 and 7).
  • Safety net: whether changes can be made and released without breaking things (questions 5, 6 and 9).
  • Hosting and people: whether the server and the knowledge are in good shape (questions 8 and 10).

For the background, read .NET 8 end of support: what it means and what to do.