Wasdk/1.8/1.8.6 release notes (#6427)

* 186 release notes, needs finalized RC version

* fix bug descriptions

* add missing fix and enum

* add N/A enum

* use component team provided text for split menu flyout

* mention onnx runtime update

* fix typo in 180

* nit: formatting

* nit: capitalization

* flat c mention

* remove internal flat c lingo

* Update WinML CMake support wording

* add api diff

* add final nuget version

* Update hub/apps/windows-app-sdk/downloads.md

* Update hub/apps/windows-app-sdk/release-channels.md

* Update hub/apps/windows-app-sdk/release-channels.md

* Update hub/apps/windows-app-sdk/release-notes/windows-app-sdk-1-8.md

* Fix release notes link for version 1.8.6

fix bookmark

* Update release date and version number for 1.8.6

* Update release notes link for version 1.8.6

* update nuget version and release date

---------

Co-authored-by: Roy <[email protected]>
Co-authored-by: KB <[email protected]>

Author: 3 people

hub/apps/windows-app-sdk/downloads.md

@@ -17,6 +17,7 @@ This page provides links to the *latest* downloads of the [Windows App SDK](inde
 
 | Version | Runtime downloads |
 |--|--|
+| **1.8.6 (1.8.260317003)**  <br/> 03/18/2026  <br/> [Release notes](./release-notes/windows-app-sdk-1-8.md?pivots=stable#version-186-18260317003) <br/> [Source](https://github.com/microsoft/microsoft-ui-xaml/releases/tag/winui3%2Frelease%2F1.8.6) | [Installer (x64)](https://aka.ms/windowsappsdk/1.8/1.8.260317003/windowsappruntimeinstall-x64.exe)  <br/> [Installer (x86)](https://aka.ms/windowsappsdk/1.8/1.8.260317003/windowsappruntimeinstall-x86.exe)  <br/> [Installer (arm64)](https://aka.ms/windowsappsdk/1.8/1.8.260317003/windowsappruntimeinstall-arm64.exe)  <br/> [Redistributable (ZIP)](https://aka.ms/windowsappsdk/1.8/1.8.260317003/Microsoft.WindowsAppRuntime.Redist.1.8.zip) |
 | **1.8.5 (1.8.260209005)**  <br/> 02/10/2026  <br/> [Release notes](./release-notes/windows-app-sdk-1-8.md?pivots=stable) <br/> [Source](https://github.com/microsoft/microsoft-ui-xaml/releases/tag/winui3%2Frelease%2F1.8.5) | [Installer (x64)](https://aka.ms/windowsappsdk/1.8/1.8.260209005/windowsappruntimeinstall-x64.exe)  <br/> [Installer (x86)](https://aka.ms/windowsappsdk/1.8/1.8.260209005/windowsappruntimeinstall-x86.exe)  <br/> [Installer (arm64)](https://aka.ms/windowsappsdk/1.8/1.8.260209005/windowsappruntimeinstall-arm64.exe)  <br/> [Redistributable (ZIP)](https://aka.ms/windowsappsdk/1.8/1.8.260209005/Microsoft.WindowsAppRuntime.Redist.1.8.zip) |
 | **1.8.4 (1.8.260101001)**  <br/> 01/13/2026  <br/> [Release notes](./release-notes/windows-app-sdk-1-8.md?pivots=stable) <br/> [Source](https://github.com/microsoft/microsoft-ui-xaml/releases/tag/winui3%2Frelease%2F1.8.4) | [Installer (x64)](https://aka.ms/windowsappsdk/1.8/1.8.260101001/windowsappruntimeinstall-x64.exe)  <br/> [Installer (x86)](https://aka.ms/windowsappsdk/1.8/1.8.260101001/windowsappruntimeinstall-x86.exe)  <br/> [Installer (arm64)](https://aka.ms/windowsappsdk/1.8/1.8.260101001/windowsappruntimeinstall-arm64.exe)  <br/> [Redistributable (ZIP)](https://aka.ms/windowsappsdk/1.8/1.8.260101001/Microsoft.WindowsAppRuntime.Redist.1.8.zip) |
 | **1.8.3 (1.8.251106002)**  <br/> 11/11/2025  <br/> [Release notes](./release-notes/windows-app-sdk-1-8.md?pivots=stable) <br/> [Source](https://github.com/microsoft/microsoft-ui-xaml/releases/tag/winui3%2Frelease%2F1.8.3) | [Installer (x64)](https://aka.ms/windowsappsdk/1.8/1.8.251106002/windowsappruntimeinstall-x64.exe)  <br/> [Installer (x86)](https://aka.ms/windowsappsdk/1.8/1.8.251106002/windowsappruntimeinstall-x86.exe)  <br/> [Installer (arm64)](https://aka.ms/windowsappsdk/1.8/1.8.251106002/windowsappruntimeinstall-arm64.exe)  <br/> [Redistributable (ZIP)](https://aka.ms/windowsappsdk/1.8/1.8.251106002/Microsoft.WindowsAppRuntime.Redist.1.8.zip) |

hub/apps/windows-app-sdk/release-channels.md

@@ -13,7 +13,7 @@ The latest version of the Windows App SDK ships via three release channels: Expe
 
 |   | Channel | Description | Release cadence | Supported? | Latest release |
 |--:|--|--|--|:--:|--|
-| **✅** | **Stable** | Production-ready channel intended for apps in market. Includes only stable, supported APIs suitable for long-term use. | No more than every six months  <br/> *(plus servicing updates as needed)* | Yes | **1.8.5 (1.8.260204001)** <br/> Released: 02/10/2026 <br/> [Release notes](./release-notes/windows-app-sdk-1-8.md?pivots=stable#version-185-18260209005) |
+| **✅** | **Stable** | Production-ready channel intended for apps in market. Includes only stable, supported APIs suitable for long-term use. | No more than every six months  <br/> *(plus servicing updates as needed)* | Yes | **1.8.6 (1.8.260317003)** <br/> Released: 03/18/2026 <br/> [Release notes](./release-notes/windows-app-sdk-1-8.md?pivots=stable#version-186-18260317003) |
 | **❇️** | **Preview** | Early look at the next Stable release. May introduce breaking API changes before final stabilization. | At least one preview for each Stable release | No | **2.0 Preview (2.0-preview)** <br/> Released: 02/13/2026 <br/>  [Release Notes](release-notes/windows-app-sdk-2-0.md#windows-app-sdk-200-preview1-release-notes) ** |
 | **🔄** | **Experimental** | Early-stage features under active development. APIs may change, be removed, or never ship. Intended for exploration and feedback only. | Published as needed to gather feedback on prototypes and early designs | No | **2.0 Experimental 6 (2.0.0-experimental6)** <br/> Released: 03/13/2026 <br/> [Release notes](./release-notes/windows-app-sdk-2-0.md?pivots=experimental#version-20-experimental-6-200-experimental6) |
 
@@ -49,7 +49,7 @@ The Windows App SDK has a lifecycle. A lifecycle begins when a version or servic
 
 | Windows App SDK version | Original release date | Latest patch version | Patch release date | Support level  | End of servicing |
 | ----------------------- | --------------------- | -------------------- | ------------------ | -------------- | ---------------- |
-| 1.8                     | 09/09/2025            | 1.8.260101001        | 01/13/2026         | Current        | 09/09/2026       |
+| 1.8                     | 09/09/2025            | 1.8.260317003        | 03/18/2026         | Current        | 09/09/2026       |
 | 1.7                     | 03/18/2025            | 1.7.260224002        | 03/10/2026         | Maintenance    | 03/18/2026       |
 | 1.6                     | 09/04/2024            | 1.6.250602001        | 06/10/2025         | Out of Support | 09/04/2025       |
 | 1.5                     | 02/29/2024            | 1.5.250108004        | 01/15/2025         | Out of Support | 02/28/2025       |

hub/apps/windows-app-sdk/release-notes/windows-app-sdk-1-8.md

@@ -15,6 +15,63 @@ zone_pivot_groups: wasdk-release-channels
 :::zone pivot="stable"
 
 
+## Version 1.8.6 (1.8.260317003)
+
+Released: **March 18, 2026** <br><br>
+
+
+<details><summary>New SplitMenuFlyoutItem Control</summary>
+
+>
+> The new **SplitMenuFlyoutItem** control is designed to provide a split button experience within a menu flyout. This control will enable developers to expose a default primary action while also offering additional options through a submenu, ideal for condensing complex functionality into a smaller footprint and saving overall menu length. For more information, see GitHub spec [10862](https://github.com/microsoft/microsoft-ui-xaml/pull/10862). ([RuntimeCompatibilityChange](/windows/windows-app-sdk/api/winrt/microsoft.windows.applicationmodel.windowsappruntime.runtimecompatibilityoptions.disabledchanges): SplitMenuFlyoutItem_Available)
+>
+
+</details>
+
+<details><summary>Windows ML CMake support</summary>
+
+>
+> Windows ML can now be used from C++ projects using CMake. See the [Get started page](/windows/ai/new-windows-ml/get-started) to learn more.
+>
+
+</details>
+
+<details><summary>Updated ONNX Runtime</summary>
+
+>
+> The version of ONNX Runtime has been updated to 1.23.4. See [ONNX Runtime versions](/windows/ai/new-windows-ml/onnx-versions) for more info.
+>
+
+</details>
+
+<details><summary>Bug fixes</summary>
+
+>
+> * Fixed a pointer arithmetic issue in the app-instance activation-redirection shared-memory queue that could cause incorrect behavior when using `AppInstance.RedirectActivationTo`. ([RuntimeCompatibilityChange](/windows/windows-app-sdk/api/winrt/microsoft.windows.applicationmodel.windowsappruntime.runtimecompatibilityoptions.disabledchanges): AppLifecycle_SharedMemoryRedirectionQueueFix)
+> * Fixed an issue in the deployment manager where activity data was being incorrectly reset during package installation and license operations. ([RuntimeCompatibilityChange](/windows/windows-app-sdk/api/winrt/microsoft.windows.applicationmodel.windowsappruntime.runtimecompatibilityoptions.disabledchanges): DeploymentManager_ActivityCollectionFix)
+> * Improved diagnosability for Text Intelligence APIs used in Windows AI scenarios. ([RuntimeCompatibilityChange](/windows/windows-app-sdk/api/winrt/microsoft.windows.applicationmodel.windowsappruntime.runtimecompatibilityoptions.disabledchanges): TextIntelligence_Insights)
+> * Fixed a visual alignment issue with `AppBarToggleButton` in `CommandBarFlyout` secondary commands. ([RuntimeCompatibilityChange](/windows/windows-app-sdk/api/winrt/microsoft.windows.applicationmodel.windowsappruntime.runtimecompatibilityoptions.disabledchanges): N/A, XAML control template fix)
+>
+
+</details>
+
+<details><summary>New or updated APIs</summary>
+
+>
+> This release includes the following new APIs compared to the 1.8.5 release:
+> ```
+> Microsoft.UI.Xaml.Automation.Peers
+> 
+>     SplitMenuFlyoutItemAutomationPeer
+> ```
+> ```
+> Microsoft.UI.Xaml.Controls
+> 
+>     SplitMenuFlyoutItem
+> ```
+</details>
+
+
 ## Version 1.8.5 (1.8.260209005)
 
 Released: **February 10, 2026** <br><br>
@@ -2208,4 +2265,4 @@ Released: **April 16, 2025** <br><br>
 
 </details>
 
-:::zone-end
+:::zone-end