Per Microsoft's documentation as fetched on 19 October 2026, Azure Functions supports only version 4.x of the runtime host. Support for version 1.x ended on 14 September 2026, versions 2.x and 3.x are also unsupported, and the .NET in-process model is scheduled to end on 10 November 2026. Check your function apps against those dates.
What Microsoft states
The runtime versions page says Azure Functions currently supports only version 4.x. It says support for 1.x ended on September 14, 2026 and that 2.x and 3.x are no longer supported. It adds that function apps still on the end-of-life v3 runtime on Linux in a Consumption plan stop running after September 30, 2026, and that the Linux Consumption hosting option itself is retiring on 30 September 2028, with Microsoft advising a move to Flex Consumption. Apps on Windows in a Consumption plan are not currently affected.
For .NET, the page says support for the in-process model ends on November 10, 2026, and it recommends moving to the isolated worker model. In its tables, .NET 8 and .NET 9 show an expected end of support of November 10, 2026, and .NET 10 shows November 14, 2028. The in-process model supports only .NET 8.
Why it matters for dependencies
Out-of-support runtimes stop receiving fixes from the platform vendor. And the dependencies in your app, such as NuGet, npm or PyPI packages, are your responsibility regardless. When you must move the runtime, dependency versions often have to move with it, because older packages may not target the new framework.
Treat a runtime migration as a dependency review too.
A checklist for each function app
| Check | Why |
|---|---|
| Runtime version (v4 expected) | Anything else is unsupported per Microsoft |
| Hosting plan | Linux Consumption has a retirement date |
| Language and language version | Compare with the support table |
| .NET execution model | In-process ends 10 November 2026 |
| Extension bundle and package versions | Part of your supply chain |
| Owner and last deploy date | Someone must act |
Steps for a migration
- Inventory all apps across subscriptions, including old test apps.
- Sort by risk: unsupported runtime first, then those near an end date.
- Read the migration guide Microsoft links for your case.
- Update dependencies to versions that target the new framework or runtime, and read changelogs.
- Test in a staging slot or separate app, including triggers and bindings.
- Switch and monitor. Keep the rollback path for a short, defined period, then remove it.
Do not stop at the host
Microsoft's table is about the host runtime and language versions. The rest of the stack, including extension bundles and third party packages, has its own release streams. For the extension side, see Azure Functions extension supply chain.
Try it yourself
Open the vulnerability management demo and filter by status. Apps on an unsupported runtime belong in the same queue as known vulnerabilities, because both stop being fixable the same way.
Click through it at your own pace, or open it full screen.
Where Safeguard fits
Safeguard's asset discovery and dependency scanning help list what you run and which packages each app contains, so a runtime move comes with a dependency plan. Free scan: gold.safeguard.sh/scan.
Quick check
Is runtime v3 still supported on Azure Functions?
No. Microsoft says versions 2.x and 3.x are no longer supported, and only 4.x is supported.
When does the .NET in-process model end?
Microsoft's page says support ends on November 10, 2026. Check the live page for any change.
Sources
Last reviewed: 19 October 2026.
