diff --git a/.github/workflows/boj-build.yml b/.github/workflows/boj-build.yml
index 144e367..c10b761 100644
--- a/.github/workflows/boj-build.yml
+++ b/.github/workflows/boj-build.yml
@@ -10,7 +10,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - name: Checkout
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
       - name: Trigger BoJ Server (Casket/ssg-mcp)
         run: |
           # Send a secure trigger to boj-server to build this repository
diff --git a/.github/workflows/casket-pages.yml b/.github/workflows/casket-pages.yml
index c5617b8..575032b 100644
--- a/.github/workflows/casket-pages.yml
+++ b/.github/workflows/casket-pages.yml
@@ -21,10 +21,10 @@ jobs:
     timeout-minutes: 30
     steps:
       - name: Checkout
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v4
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v4
 
       - name: Checkout casket-ssg
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v4
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v4
         with:
           repository: hyperpolymath/casket-ssg
           path: .casket-ssg
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 48325d4..0f8a8e2 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -36,7 +36,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Initialize CodeQL
         uses: github/codeql-action/init@c6f931105cb2c34c8f901cc885ba1e2e259cf745 # v3
diff --git a/.github/workflows/dogfood-gate.yml b/.github/workflows/dogfood-gate.yml
index 4bede08..0d4a2a1 100644
--- a/.github/workflows/dogfood-gate.yml
+++ b/.github/workflows/dogfood-gate.yml
@@ -26,7 +26,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Check for A2ML files
         id: detect
@@ -71,7 +71,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Check for K9 files
         id: detect
@@ -121,7 +121,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Scan for invisible characters
         id: lint
@@ -186,7 +186,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Check for Groove manifest
         id: groove
@@ -245,7 +245,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Enforce pure-coordinator boundary
         run: bash hooks/validate-coordinator-boundary.sh
@@ -269,7 +269,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+        uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Generate dogfooding scorecard
         run: |
diff --git a/.github/workflows/scorecard-enforcer.yml b/.github/workflows/scorecard-enforcer.yml
index b290f29..6f888bb 100644
--- a/.github/workflows/scorecard-enforcer.yml
+++ b/.github/workflows/scorecard-enforcer.yml
@@ -34,7 +34,7 @@ jobs:
       security-events: write
       id-token: write  # For OIDC
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           persist-credentials: false
 
@@ -64,7 +64,7 @@ jobs:
     permissions:
       contents: read
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
         with:
           persist-credentials: false
 
@@ -95,7 +95,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Check SECURITY.md exists
         run: |
diff --git a/.github/workflows/semgrep.yml b/.github/workflows/semgrep.yml
index 0cb4e8e..0590e24 100644
--- a/.github/workflows/semgrep.yml
+++ b/.github/workflows/semgrep.yml
@@ -23,7 +23,7 @@ jobs:
     container:
       image: semgrep/semgrep
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Run Semgrep
         run: semgrep scan --sarif --output=semgrep.sarif --config=auto .
diff --git a/.github/workflows/workflow-linter.yml b/.github/workflows/workflow-linter.yml
index 994df98..7a2c60f 100644
--- a/.github/workflows/workflow-linter.yml
+++ b/.github/workflows/workflow-linter.yml
@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v4
+      - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v4
 
       - name: Check SPDX headers
         run: |