diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 42a355b..0a07793 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,20 +9,24 @@ permissions:
 
 jobs:
   build_pack_ios:
-    runs-on: macos-latest
+    runs-on: macos-15
     steps:
       - uses: actions/checkout@v4
 
+      - name: Select Xcode 26.3
+        # Pinned: the native artifacts must stay consumable by Xcode 26.3 toolchains.
+        run: sudo xcode-select --switch /Applications/Xcode_26.3.app/Contents/Developer
+
       - uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: "10.0.x"
+          dotnet-version: "10.0.203"
 
       - name: Validate feature selection
         run: bash tests/validate-feature-selection.sh
 
       - name: Install iOS workload
         run: |
-          dotnet workload install ios
+          dotnet workload install ios --version 10.0.203
 
       - name: Cache NuGet
         uses: actions/cache@v4
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index fa519bb..15bdae9 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -17,7 +17,7 @@ permissions:
 
 jobs:
   pack_and_publish:
-    runs-on: macos-latest
+    runs-on: macos-15
     permissions:
       contents: read
       packages: write
@@ -67,16 +67,20 @@ jobs:
           echo "Package version: ${VERSION}"
           echo "Publish target: ${PUBLISH_TARGET}"
 
+      - name: Select Xcode 26.3
+        # Pinned: the native artifacts must stay consumable by Xcode 26.3 toolchains.
+        run: sudo xcode-select --switch /Applications/Xcode_26.3.app/Contents/Developer
+
       - uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: "10.0.x"
+          dotnet-version: "10.0.203"
 
       - name: Validate feature selection
         run: bash tests/validate-feature-selection.sh
 
       - name: Install iOS workload
         run: |
-          dotnet workload install ios
+          dotnet workload install ios --version 10.0.203
 
       - name: Cache NuGet
         uses: actions/cache@v4
diff --git a/.github/workflows/sample-ios.yml b/.github/workflows/sample-ios.yml
index 5800a95..80c3744 100644
--- a/.github/workflows/sample-ios.yml
+++ b/.github/workflows/sample-ios.yml
@@ -19,37 +19,18 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - name: Setup Xcode 26.0
-        uses: maxim-lobanov/setup-xcode@v1
-        with:
-          xcode-version: "26.0"
+      - name: Select Xcode 26.3
+        # Pinned: the native artifacts must stay consumable by Xcode 26.3 toolchains.
+        run: sudo xcode-select --switch /Applications/Xcode_26.3.app/Contents/Developer
 
       - uses: actions/setup-dotnet@v4
         with:
-          dotnet-version: "10.0.x"
-
-      - name: Pin workload update mode (manifests)
-        shell: bash
-        run: |
-          dotnet workload config --update-mode manifests
-          dotnet workload config --update-mode
-
-      - name: Purge incompatible iOS packs (cache defense)
-        shell: bash
-        run: |
-          set -euo pipefail
-          PACKS_DIR="$HOME/.dotnet/packs"
-          for v in 26.2; do
-            if [ -d "$PACKS_DIR" ] && compgen -G "$PACKS_DIR/Microsoft.iOS.*_${v}*" > /dev/null; then
-              echo "Removing cached iOS ${v} packs from $PACKS_DIR"
-              rm -rf "$PACKS_DIR"/Microsoft.iOS.*_${v}*
-            fi
-          done
+          dotnet-version: "10.0.203"
 
       - name: Install iOS workload
         shell: bash
         run: |
-          dotnet workload install ios --skip-manifest-update
+          dotnet workload install ios --version 10.0.203
 
       - name: Diagnostics (.NET + workloads)
         shell: bash