.NET 8 and .NET 9 reach end of support today
Microsoft stops shipping security patches for both versions from 10 November 2026, with .NET 10 as the only supported upgrade path.
.NET 8 and .NET 9 both reach end of support today, 10 November 2026. .NET 8 was a Long Term Support release, covered for 36 months since its November 2023 launch. .NET 9 was a Standard Term Support release, covered for 24 months since November 2024. Both windows close on the same day.
Apps built on either version keep running, but Microsoft stops issuing security patches, servicing updates and technical support from here. The one exception: because today is also Patch Tuesday, .NET 8 and .NET 9 can each still get one last fix if a known critical issue is already in the pipeline. After that, nothing. Microsoft’s recommended path is .NET 10, an LTS release supported through November 2028, and the migration is a one-line change for most projects.
<TargetFramework>net10.0</TargetFramework>Why it matters: anyone still shipping on .NET 8 or .NET 9 is now running without a safety net for new vulnerabilities. .NET 8’s three-year LTS window made it easy to assume there was more runway than there was, and .NET 9 developers get even less warning given its shorter STS cycle. Either way, the fix is to retarget to .NET 10 before the next critical bug lands with nowhere to patch it.