diff --git a/.github/workflows/CI-native.yml b/.github/workflows/CI-native.yml
index d18f31aec7..6c77c9a10a 100644
--- a/.github/workflows/CI-native.yml
+++ b/.github/workflows/CI-native.yml
@@ -58,7 +58,7 @@ jobs:
     runs-on: windows-latest
     steps:
       - name: Checkout Files
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: checkout
 
       - name: Build and run native tests
diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 82316a7125..2ef7b55d3c 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -20,7 +20,7 @@ jobs:
     runs-on: windows-latest
     steps:
       - name: Checkout Files
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: checkout
 
       - name: Build managed (with tests)
diff --git a/.github/workflows/CommitMessage.yml b/.github/workflows/CommitMessage.yml
index 28dced92fa..78e5cfcb0e 100644
--- a/.github/workflows/CommitMessage.yml
+++ b/.github/workflows/CommitMessage.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@v6
       with:
         fetch-depth: 0
     - name: Install dependencies
diff --git a/.github/workflows/base-installer-cd.yml b/.github/workflows/base-installer-cd.yml
index f752cc326d..4886131052 100644
--- a/.github/workflows/base-installer-cd.yml
+++ b/.github/workflows/base-installer-cd.yml
@@ -62,14 +62,14 @@ jobs:
           echo "FW_BUILD_NUMBER=$combined" >> $env:GITHUB_ENV
 
       - name: Checkout Files
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: checkout
         with:
           ref: ${{ github.event.inputs.fw_ref || github.ref }}
           fetch-depth: 0
 
       - name: Checkout Helps
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: helps-checkout
         with:
           repository: 'sillsdev/FwHelps'
@@ -78,7 +78,7 @@ jobs:
           path: 'DistFiles/Helps'
 
       - name: Checkout PatchableInstaller
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: installer-checkout
         with:
           repository: 'sillsdev/genericinstaller'
@@ -87,7 +87,7 @@ jobs:
           path: 'PatchableInstaller'
 
       - name: Checkout Localizations
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: loc-checkout
         with:
           repository: 'sillsdev/FwLocalizations'
@@ -95,7 +95,7 @@ jobs:
           fetch-depth: 0
           path: 'Localizations'
       - name: Checkout liblcm
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: liblcm-checkout
         with:
           repository: 'sillsdev/liblcm'
diff --git a/.github/workflows/check-whitespace.yml b/.github/workflows/check-whitespace.yml
index 53700f9f15..6bdf2382f6 100644
--- a/.github/workflows/check-whitespace.yml
+++ b/.github/workflows/check-whitespace.yml
@@ -13,7 +13,7 @@ jobs:
     check-whitespace:
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v4
+            - uses: actions/checkout@v6
               with:
                   fetch-depth: 0
 
diff --git a/.github/workflows/copilot-setup-steps.yml b/.github/workflows/copilot-setup-steps.yml
index ff345f36ba..3cf5fe757c 100644
--- a/.github/workflows/copilot-setup-steps.yml
+++ b/.github/workflows/copilot-setup-steps.yml
@@ -87,7 +87,7 @@ jobs:
 
     steps:
       - name: Checkout repo
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       # ================================================================
       # CACHING - speeds up repeat runs significantly
diff --git a/.github/workflows/link-check.yml b/.github/workflows/link-check.yml
index c139b35660..88c73c9981 100644
--- a/.github/workflows/link-check.yml
+++ b/.github/workflows/link-check.yml
@@ -9,7 +9,7 @@ jobs:
         runs-on: ubuntu-latest
         steps:
             - name: Checkout
-              uses: actions/checkout@v4
+              uses: actions/checkout@v6
             - name: Link check with lychee (non-blocking)
               uses: lycheeverse/lychee-action@v2.8.0
               with:
diff --git a/.github/workflows/openspec-validate.yml b/.github/workflows/openspec-validate.yml
index 5897818ea2..f89af8796b 100644
--- a/.github/workflows/openspec-validate.yml
+++ b/.github/workflows/openspec-validate.yml
@@ -10,7 +10,7 @@ jobs:
   validate-refs:
     runs-on: windows-latest
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v6
       - name: Validate OpenSpec cross-references
         shell: pwsh
         run: |
diff --git a/.github/workflows/patch-installer-cd.yml b/.github/workflows/patch-installer-cd.yml
index 9d65493ddf..1f5ab04e5b 100644
--- a/.github/workflows/patch-installer-cd.yml
+++ b/.github/workflows/patch-installer-cd.yml
@@ -77,14 +77,14 @@ jobs:
           echo "BuildVersionSegment=$combined" >> $env:GITHUB_ENV
 
       - name: Checkout Files
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: checkout
         with:
           ref: ${{ github.event.inputs.fw_ref || github.ref }}
           fetch-depth: 0
 
       - name: Checkout Helps
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: helps-checkout
         with:
           repository: 'sillsdev/FwHelps'
@@ -93,7 +93,7 @@ jobs:
           path: 'DistFiles/Helps'
 
       - name: Checkout PatchableInstaller
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: installer-checkout
         with:
           repository: 'sillsdev/genericinstaller'
@@ -102,7 +102,7 @@ jobs:
           path: 'PatchableInstaller'
 
       - name: Checkout Localizations
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: loc-checkout
         with:
           repository: 'sillsdev/FwLocalizations'
@@ -110,7 +110,7 @@ jobs:
           fetch-depth: 0
           path: 'Localizations'
       - name: Checkout liblcm
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         id: liblcm-checkout
         with:
           repository: 'sillsdev/liblcm'