ASP.NET 10.0.9

Microsoft has shipped ASP.NET Core 10.0.9, the latest servicing update for the ASP.NET Core 10.x line. This patch release ships as part of .NET 10.0.9 and focuses on bug fixes, security hardening, and reliability improvements across the framework.

Overview of Changes

ASP.NET Core 10.0.9 brings a set of targeted fixes addressing issues reported by the community and discovered through internal testing. Key areas of improvement include request handling, build infrastructure, and template tooling.

Bug Fixes and Improvements

• Antiforgery token preservation — Fixed a scenario where antiforgery tokens were not properly preserved under specific request conditions, strengthening CSRF protection in form-based authentication workflows
• Disconnection handling — Server methods are now properly detached when a disconnection is confirmed, preventing resource leaks in long-running SignalR and WebSocket connections
• NU1903 suppression fix — Adjusted NuGet warning suppression to use NoWarn instead of WarningsNotAsErrors, giving developers finer-grained control over their build output
• arm64 linker workaround removed — A temporary workaround for an arm64 forwarder linker issue has been reverted following an upstream fix in the .NET runtime
• MCP Server template — Added the Model Context Protocol (MCP) server project template to the .NET 10 SDK, enabling AI tool integration and agentic development scenarios
• Build infrastructure — Node.js version pinned to 24.14.1 for consistent CI/CD pipeline results across all platforms

Breaking Changes

There are no breaking changes in this release. ASP.NET Core 10.0.9 is a fully compatible servicing update. Existing applications can upgrade by updating their NuGet package references to version 10.0.9.

How to Upgrade

Update your projects by running dotnet update in your project directory, or update your package references manually to version 10.0.9. The update is available on NuGet.org and can also be applied via the Visual Studio NuGet package manager.