# .NET 8 and .NET 9 both leave support on November 10, 2026: plan the move to .NET 10 now > Microsoft ends support for .NET 8 (LTS) and .NET 9 (STS) on the same day, November 10, 2026. Apps keep running, but no further security fixes are issued. .NET 10 is the LTS release supported to November 14, 2028. - Canonical URL: https://update.dsesecurity.com/updates/dotnet-8-and-9-end-of-support-november-10-2026/ - Publisher: Detection Systems & Engineering (DSE Security) - Author: DSE Security Editorial Team - Published: 2026-10-18T21:00:02+00:00 - Modified: 2026-10-18T22:22:06+00:00 - Last reviewed by DSE: 2026-10-18 - Resource type: Briefing - DSE priority: Important - Topics: Cybersecurity, IT - Reading time: 2 minutes ## What you need to know Microsoft ends support for .NET 8 (LTS) and .NET 9 (STS) on the same day, November 10, 2026. Apps keep running, but no further security fixes are issued. .NET 10 is the LTS release supported to November 14, 2028. ## Potentially affected Custom web applications, services, APIs, desktop tools and vendor-supplied software built on .NET 8 or .NET 9, together with their build machines and hosting environments. ## DSE recommendation DSE recommends inventorying every .NET 8 and .NET 9 workload this month and scheduling each one for retargeting, vendor replacement or a documented exception. ## Article Microsoft ends support for .NET 8 (LTS) and .NET 9 (STS) on the same day, November 10, 2026. Apps keep running, but no further security fixes are issued. .NET 10 is the LTS release supported to November 14, 2028. ## Source facts Microsoft’s [.NET support policy](https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-core) lists November 10, 2026 as the end of support for both .NET 8, a Long Term Support release, and .NET 9, a Standard Term Support release, and November 14, 2028 for .NET 10. LTS releases get free support and patches for three years and STS releases for two, and a system must have the latest patch installed to remain supported. The [.NET team’s announcement](https://devblogs.microsoft.com/dotnet/dotnet-8-9-end-of-support/) says applications built on .NET 8 or .NET 9 will continue to run after that date, but no new security updates will be issued and technical support ends. Upgrading means changing the project’s TargetFramework to net10.0 and also updating development and hosting environments. For third-party .NET applications, Microsoft recommends asking the developer or vendor for a version that uses .NET 10. ## Applicability Use this for in-house and custom-developed .NET applications, hosted web apps, scheduled services and line-of-business tools, and for packaged software whose vendor documents a .NET 8 or .NET 9 runtime dependency. ## DSE recommendation DSE recommends inventorying every .NET 8 and .NET 9 workload this month and scheduling each one for retargeting, vendor replacement or a documented exception. Record the runtime, hosting platform, owner and test plan per application. Retarget to net10.0 in a branch, review the published breaking changes, update build agents and servers, and ask each software vendor in writing for a .NET 10 release date. Any workload still on .NET 8 or .NET 9 after November 10 needs an owner-approved risk acceptance and compensating controls. ## Verification Confirm the deployed application reports the .NET 10 runtime, run its regression and security tests in staging, and check that build pipelines no longer restore .NET 8 or .NET 9 SDKs. After cut-over, remove unused .NET 8 and .NET 9 runtimes from servers and record the change. ## Official references [Microsoft .NET — .NET and .NET Core Support Policy](https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-core). [.NET Blog — .NET 8 and .NET 9 will reach end of support on November 10, 2026](https://devblogs.microsoft.com/dotnet/dotnet-8-9-end-of-support/). Reviewed October 18, 2026. ## Primary reference - Name: Microsoft .NET — .NET and .NET Core Support Policy - Authority: dotnet.microsoft.com - URL: https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-core - Source publication date: Not stated by the source ## Citation and use Preferred citation: “.NET 8 and .NET 9 both leave support on November 10, 2026: plan the move to .NET 10 now,” DSE Security, https://update.dsesecurity.com/updates/dotnet-8-and-9-end-of-support-november-10-2026/ Publishing principles: https://update.dsesecurity.com/updates/dse-updates-editorial-methodology/ Usage and citation policy: https://update.dsesecurity.com/usage/ Copyright © 2026 Detection Systems & Engineering. All rights reserved.