diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index bf97f4c..d67d3dc 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -39,15 +39,15 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v7.0.1
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
 
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@v4.38.0
+        uses: github/codeql-action/init@b96794f015dfd88f77b49b1c93e0fa7110f94c63  # v4.38.0
         with:
           languages: ${{ matrix.language }}
           build-mode: ${{ matrix.build-mode }}
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@v4.38.0
+        uses: github/codeql-action/analyze@b96794f015dfd88f77b49b1c93e0fa7110f94c63  # v4.38.0
         with:
           category: "/language:${{ matrix.language }}"
diff --git a/.github/workflows/instant-sync.yml b/.github/workflows/instant-sync.yml
index 8a40867..9445e06 100644
--- a/.github/workflows/instant-sync.yml
+++ b/.github/workflows/instant-sync.yml
@@ -20,7 +20,7 @@ jobs:
     timeout-minutes: 15
     steps:
       - name: Trigger Propagation
-        uses: peter-evans/repository-dispatch@v4.0.1
+        uses: peter-evans/repository-dispatch@28959ce8df70de7be546dd1250a005dd32156697  # v4.0.1
         with:
           token: ${{ secrets.FARM_DISPATCH_TOKEN }}
           repository: hyperpolymath/.git-private-farm
diff --git a/.github/workflows/pages.yml b/.github/workflows/pages.yml
index 4e9589c..b2b46f4 100644
--- a/.github/workflows/pages.yml
+++ b/.github/workflows/pages.yml
@@ -22,9 +22,9 @@ jobs:
       image: ghcr.io/stefan-hoeck/idris2-pack@sha256:f0758996a931fb35d9ecb1de273c4d59dabe2a09b433afc7e357f65a08b7e1ff
     steps:
       - name: Checkout Site
-        uses: actions/checkout@v7.0.1
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
       - name: Checkout Ddraig SSG
-        uses: actions/checkout@v7.0.1
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
         with:
           repository: hyperpolymath/ddraig-ssg
           path: .ddraig-ssg
@@ -41,7 +41,7 @@ jobs:
           fi
           ./.ddraig-ssg/build/exec/ddraig build src _site https://hyperpolymath.github.io/${GITHUB_REPOSITORY#*/}
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v5.0.0
+        uses: actions/upload-pages-artifact@fc324d3547104276b827a68afc52ff2a11cc49c9  # v5.0.0
         with:
           path: '_site'
   deploy:
@@ -54,4 +54,4 @@ jobs:
     steps:
       - name: Deploy to GitHub Pages
         id: deployment
-        uses: actions/deploy-pages@v5.0.1
+        uses: actions/deploy-pages@368f82528645a54fb793d4d04e342629a3f51346  # v5.0.1
diff --git a/.github/workflows/push-email-notify.yml b/.github/workflows/push-email-notify.yml
index 8d1f093..521f1e5 100644
--- a/.github/workflows/push-email-notify.yml
+++ b/.github/workflows/push-email-notify.yml
@@ -40,7 +40,7 @@ jobs:
     timeout-minutes: 5
     steps:
       - name: Send push notification email
-        uses: hyperpolymath/smtp-notify-action@v0.3.0 # NOSONAR — pin authority is actions.lock (sha1-ede1191ef6ff3ac02c4f4d9efdf837ee517e11d7)
+        uses: hyperpolymath/smtp-notify-action@22e7bdb322c430c1d0dac6b3bb307f4bb139d0be  # NOSONAR — pin authority is actions.lock (sha1-ede1191ef6ff3ac02c4f4d9efdf837ee517e11d7)
         with:
           server_address: ${{ secrets.SMTP_HOST }}
           server_port: ${{ secrets.SMTP_PORT }}