diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index b8509e4..977266d 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -23,10 +23,10 @@ jobs:
         go-version: ['1.25']
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
         with:
           go-version: ${{ matrix.go-version }}
           cache: true  # Enable built-in caching
@@ -38,7 +38,7 @@ jobs:
         run: make build
 
       - name: Upload build artifacts
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: gac-${{ matrix.os }}-${{ matrix.go-version }}
           path: build/gac*
diff --git a/.github/workflows/pr-checks.yml b/.github/workflows/pr-checks.yml
index d781f00..a961103 100644
--- a/.github/workflows/pr-checks.yml
+++ b/.github/workflows/pr-checks.yml
@@ -21,10 +21,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
         with:
           go-version: '1.26'
           cache: true  # Built-in caching for go.mod and go.sum
@@ -42,7 +42,7 @@ jobs:
         run: go tool cover -html=coverage.out -o coverage.html
 
       - name: Upload coverage artifacts
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: coverage-report
           path: |
@@ -56,16 +56,16 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
         with:
           go-version: '1.26'
           cache: true
 
       - name: Run golangci-lint
-        uses: golangci/golangci-lint-action@v9
+        uses: golangci/golangci-lint-action@1e7e51e771db61008b38414a730f564565cf7c20 # v9
         with:
           version: latest
           args: --timeout=5m
@@ -76,10 +76,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
         with:
           go-version: '1.26'
           cache: true
@@ -88,7 +88,7 @@ jobs:
         run: make build
 
       - name: Upload build artifact
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         with:
           name: gac-binary
           path: build/gac
@@ -100,10 +100,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
         with:
           go-version: '1.26'
           cache: true
@@ -111,12 +111,12 @@ jobs:
       # Pinned to v2.23.0 (not @master) to ensure stable SARIF output
       # Update when new stable versions are released: https://github.com/securego/gosec/releases
       - name: Run Gosec Security Scanner
-        uses: securego/gosec@v2.26.1
+        uses: securego/gosec@4a3bd8af174872c778439083ded7adbf3747e770 # v2.26.1
         with:
           args: '-fmt sarif -out gosec-results.sarif ./...'
 
       - name: Upload Gosec results to GitHub Security tab
-        uses: github/codeql-action/upload-sarif@v4
+        uses: github/codeql-action/upload-sarif@68bde559dea0fdcac2102bfdf6230c5f70eb485e # v4
         if: always()
         with:
           sarif_file: gosec-results.sarif
@@ -127,7 +127,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
 
       - name: Run Trivy vulnerability scanner
         uses: aquasecurity/trivy-action@ed142fd0673e97e23eac54620cfb913e5ce36c25 # v0.36.0
@@ -138,7 +138,7 @@ jobs:
           output: 'trivy-results.sarif'
 
       - name: Upload Trivy results to GitHub Security tab
-        uses: github/codeql-action/upload-sarif@v4
+        uses: github/codeql-action/upload-sarif@68bde559dea0fdcac2102bfdf6230c5f70eb485e # v4
         if: always()
         with:
           sarif_file: 'trivy-results.sarif'
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 7af06f7..bc394a4 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -16,7 +16,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
           fetch-depth: 0  # Fetch all history for changelog generation
 
@@ -24,12 +24,12 @@ jobs:
         run: git fetch --force --tags
 
       - name: Set up Go
-        uses: actions/setup-go@v6
+        uses: actions/setup-go@4a3601121dd01d1626a1e23e37211e3254c1c06c # v6
         with:
           go-version: '1.26'
 
       - name: Cache Go modules
-        uses: actions/cache@v5
+        uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5
         with:
           path: |
             ~/.cache/go-build
@@ -39,20 +39,20 @@ jobs:
             ${{ runner.os }}-go-
 
       - name: Set up QEMU
-        uses: docker/setup-qemu-action@v4
+        uses: docker/setup-qemu-action@ce360397dd3f832beb865e1373c09c0e9f86d70a # v4
 
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@v4
+        uses: docker/setup-buildx-action@4d04d5d9486b7bd6fa91e7baf45bbb4f8b9deedd # v4
 
       - name: Login to GitHub Container Registry
-        uses: docker/login-action@v4
+        uses: docker/login-action@4907a6ddec9925e35a0a9e82d7399ccc52663121 # v4
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - name: Run GoReleaser
-        uses: goreleaser/goreleaser-action@v7
+        uses: goreleaser/goreleaser-action@1a80836c5c9d9e5755a25cb59ec6f45a3b5f41a8 # v7
         with:
           distribution: goreleaser
           version: '~> v2'
@@ -62,7 +62,7 @@ jobs:
           GITHUB_REPOSITORY_OWNER: ${{ github.repository_owner }}
 
       - name: Upload artifacts
-        uses: actions/upload-artifact@v7
+        uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v7
         if: always()
         with:
           name: release-artifacts