diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e11d27c..f494349 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -16,17 +16,18 @@ jobs:
     name: Build and Validate
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
           fetch-depth: 0
+          persist-credentials: false
 
       - name: Lint Dockerfile
-        uses: hadolint/hadolint-action@v3.3.0
+        uses: hadolint/hadolint-action@2332a7b74a6de0dda2e2221d575162eba76ba5e5 # v3.3.0
         with:
           dockerfile: .devcontainer/Dockerfile
 
       - name: Check for secrets
-        uses: gitleaks/gitleaks-action@v2
+        uses: gitleaks/gitleaks-action@ff98106e4c7b2bc287b24eaf42907196329070c7 # v2
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 
@@ -40,10 +41,12 @@ jobs:
     needs: build
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
+        with:
+          persist-credentials: false
 
       - name: Test devcontainer functionality
-        uses: devcontainers/ci@v0.3
+        uses: devcontainers/ci@b63b30de439b47a52267f241112c5b453b673db5 # v0.3
         with:
           push: never
           runCmd: |
diff --git a/.github/workflows/security.yml b/.github/workflows/security.yml
index 5e8b9fb..e2d9f11 100644
--- a/.github/workflows/security.yml
+++ b/.github/workflows/security.yml
@@ -19,9 +19,10 @@ jobs:
     name: Security and SBOM Analysis
     steps:
       - name: Checkout
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
           fetch-depth: 0
+          persist-credentials: false
 
       - name: Build Docker image for scanning
         run: |
@@ -30,7 +31,7 @@ jobs:
           echo "IMAGE_NAME=$IMAGE_NAME" >> $GITHUB_ENV
 
       - name: Run Trivy vulnerability scanner
-        uses: aquasecurity/trivy-action@v0.36.0
+        uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
         with:
           image-ref: '${{ env.IMAGE_NAME }}'
           format: 'sarif'
@@ -39,28 +40,28 @@ jobs:
           exit-code: '0'
 
       - name: Upload Trivy scan results to GitHub Security tab
-        uses: github/codeql-action/upload-sarif@v4
+        uses: github/codeql-action/upload-sarif@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4
         if: always()
         with:
           sarif_file: 'trivy-results.sarif'
           category: 'security-analysis/trivy-image'
 
       - name: Generate SBOM
-        uses: anchore/sbom-action@v0
+        uses: anchore/sbom-action@e22c389904149dbc22b58101806040fa8d37a610 # v0
         with:
           image: '${{ env.IMAGE_NAME }}'
           format: 'spdx-json'
           output-file: 'sbom.spdx.json'
 
       - name: Upload SBOM as artifact
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: sbom-${{ github.sha }}
           path: sbom.spdx.json
           retention-days: 30
 
       - name: Run Trivy filesystem scan
-        uses: aquasecurity/trivy-action@v0.36.0
+        uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
         with:
           scan-type: 'fs'
           scan-ref: '.'
@@ -70,7 +71,7 @@ jobs:
           exit-code: '0'
 
       - name: Upload filesystem scan results
-        uses: github/codeql-action/upload-sarif@v4
+        uses: github/codeql-action/upload-sarif@95e58e9a2cdfd71adc6e0353d5c52f41a045d225 # v4
         if: always()
         with:
           sarif_file: 'trivy-fs-results.sarif'