Microsoft has shipped the Visual Studio 2026 September update, a release the company says marks the beginning of a new era for its flagship development environment through deep platform integration of AI, stronger fundamentals and improved performance. "We're excited to announce the availability of the Visual Studio 2026 September update," Microsoft said in the release notes. "This release marks the beginning of a new era for Visual Studio with deep platform integration of AI, stronger fundamentals, and improved performance." ## AI From Any Provider The centerpiece of update 18.10.0, released on 8 September 2026, is Bring Your Own Key, available in preview and enabled by default across the Community, Professional and Enterprise SKUs. The feature lets developers use AI in Visual Studio with the models their teams prefer, whether through GitHub Copilot or their own model deployments, signed in to GitHub or not. "The best AI in Visual Studio is the AI you can bring with you," the release notes state. Supported providers include Microsoft Foundry, OpenAI, Anthropic and Ollama, plus custom endpoint support for OpenAI and Ollama. BYOK works with a new Agent preview built on the GitHub Copilot SDK-powered harness; the earlier BYOK experience in the previous Ask and Agent modes is no longer supported. The Git agent also gains pull request exploration. Developers can open Copilot Chat, select the Git agent and ask about a pull request, with responses including navigable links that open the corresponding comments and files directly in the pull request view. GitHub and Azure DevOps MCP servers are both supported. ## Debugging and Containers The update targets everyday debugging friction. When debugging C# if statements that use && or ||, Visual Studio now uses red and green highlighting to show which operand determined the result, helping developers understand complex branching without evaluating each expression individually. The highlighting can be disabled from the editor context menu. Container support expands beyond Docker: starting in 18.10, debugger container discovery recognizes Podman alongside Docker. Developers can attach to processes inside Podman containers for both .NET and C++ with no extra configuration. A servicing release, 18.10.1, followed on 15 September 2026, fixing a community-reported issue where the XAMLX Workflow Designer could fail to open workflows after updating, and correcting bad code generation when dereferencing a pointer to a based pointer. ## Foundations Laid in August The September release builds on the August 18.9.0 update, released on 11 August, which introduced adjustable thinking effort for supported Copilot models. Developers can choose low, medium or high reasoning depth to balance response quality against token usage, with low giving quick responses for straightforward questions and high applying deeper reasoning to tricky algorithms and hard-to-debug issues. August also delivered first-class Git submodule support, one of the most requested Git features, letting developers add, update and remove submodules directly in the IDE with a dedicated section in the Git Repository window. Submodules remain read-only by default. Organization owners gained the ability to share custom agents across repositories, and a redesigned model picker lets developers pin favorite models and view cost information, capabilities and context window sizes in one place. ## Security Patches for Crafted PDB Files Version 18.9.3, also released on 8 September, addressed a series of security advisories. Two remote code execution vulnerabilities, CVE-2026-77907 and CVE-2026-77906, involved Microsoft.DiaSymReader.Native: an unchecked COFF relocation causing a 4-byte out-of-bounds write, and malformed PDB COFF COMDAT data, both triggered by specially crafted PDB files. Further fixes covered an SQLite information disclosure flaw, an OpenSSL update, .NET elevation-of-privilege vulnerabilities, an ASP.NET Core denial-of-service issue in IIS out-of-process hosting, and two dotnet watch information disclosure flaws.