diff --git a/.github/workflows/commisery.yml b/.github/workflows/commisery.yml
index 4f83fb1..cea9cfc 100644
--- a/.github/workflows/commisery.yml
+++ b/.github/workflows/commisery.yml
@@ -21,8 +21,13 @@ jobs:
   commit-message:
     runs-on: ubuntu-latest
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@eb238b55efaa70779f274895e782ed17c84f2895 # v2.6.1
+        with:
+          egress-policy: audit
+
       - name: Run Commisery
-        uses: tomtom-international/commisery-action@v2
+        uses: tomtom-international/commisery-action@33eb2d6e7dfc53e6d3d09ea20c639b8858f75021 # v2.19.3
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           validate-pull-request: false
diff --git a/.github/workflows/dco.yml b/.github/workflows/dco.yml
index 9033ada..e4838f7 100644
--- a/.github/workflows/dco.yml
+++ b/.github/workflows/dco.yml
@@ -4,4 +4,9 @@ jobs:
   dco:
     runs-on: ubuntu-latest
     steps:
-      - uses: tisonkun/actions-dco@v1.1
+      - name: Harden Runner
+        uses: step-security/harden-runner@eb238b55efaa70779f274895e782ed17c84f2895 # v2.6.1
+        with:
+          egress-policy: audit
+
+      - uses: tisonkun/actions-dco@f1024cd563550b5632e754df11b7d30b73be54a5 # v1.1
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 031f510..693e5df 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -5,16 +5,21 @@ jobs:
     name: Cargo clippy & fmt
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - name: Harden Runner
+      uses: step-security/harden-runner@eb238b55efaa70779f274895e782ed17c84f2895 # v2.6.1
+      with:
+        egress-policy: audit
+
+    - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
     - name: Setup Rust toolchain
       run: rustup show && rustup update
     - name: cargo fmt
-      uses: actions-rs/cargo@v1
+      uses: actions-rs/cargo@844f36862e911db73fe0815f00a4a2602c279505 # v1.0.3
       with:
         command: fmt
         args: -- --check
     - name: cargo clippy
-      uses: actions-rs/cargo@v1
+      uses: actions-rs/cargo@844f36862e911db73fe0815f00a4a2602c279505 # v1.0.3
       with:
         command: clippy
         args: --all-features --tests -- -D warnings
@@ -23,14 +28,19 @@ jobs:
     name: Unused dependencies
     runs-on: ubuntu-latest
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@eb238b55efaa70779f274895e782ed17c84f2895 # v2.6.1
+        with:
+          egress-policy: audit
+
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
       - name: Install nightly toolchain
-        uses: dtolnay/rust-toolchain@nightly
+        uses: dtolnay/rust-toolchain@53c04d3685fcc3ca67ce478eb9c2ea5c051a4a63 # nightly
 
       - name: Run cargo-udeps
-        uses: aig787/cargo-udeps-action@v1
+        uses: aig787/cargo-udeps-action@1cd634a329e14ccfbccfe7c96497d14dac24a743 # v1
         with:
           version: 'latest'
           args: '--all-targets'
@@ -39,8 +49,13 @@ jobs:
     name: Cargo Audit
     runs-on: ubuntu-latest
     steps:
+      - name: Harden Runner
+        uses: step-security/harden-runner@eb238b55efaa70779f274895e782ed17c84f2895 # v2.6.1
+        with:
+          egress-policy: audit
+
       - name: Checkout repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
       - name: Install Cargo Audit
         run: cargo install cargo-audit
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 7544d16..f0de988 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -1,12 +1,20 @@
 name: Test
 on: [ push, pull_request ]
+permissions:
+  contents: read
+
 jobs:
   test:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - name: Harden Runner
+      uses: step-security/harden-runner@eb238b55efaa70779f274895e782ed17c84f2895 # v2.6.1
+      with:
+        egress-policy: audit
+
+    - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
     - name: cargo test
-      uses: actions-rs/cargo@v1
+      uses: actions-rs/cargo@844f36862e911db73fe0815f00a4a2602c279505 # v1.0.3
       with:
         command: test
         args: --all-features