diff --git a/.github/workflows/add-remove-new-fulcio.yaml b/.github/workflows/add-remove-new-fulcio.yaml
index 1f3e4c4fe..8b013534e 100644
--- a/.github/workflows/add-remove-new-fulcio.yaml
+++ b/.github/workflows/add-remove-new-fulcio.yaml
@@ -53,7 +53,7 @@ jobs:
         check-latest: true
 
     - name: Check out our repo
-      uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       with:
         path: ./src/github.com/sigstore/scaffolding
 
diff --git a/.github/workflows/codeql-analysis.yml b/.github/workflows/codeql-analysis.yml
index 3457cc245..5aa62d40a 100644
--- a/.github/workflows/codeql-analysis.yml
+++ b/.github/workflows/codeql-analysis.yml
@@ -30,7 +30,7 @@ jobs:
 
     steps:
       - name: Checkout repository
-        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
diff --git a/.github/workflows/fulcio-rekor-kind.yaml b/.github/workflows/fulcio-rekor-kind.yaml
index 6cd507d56..edc2ad8ea 100644
--- a/.github/workflows/fulcio-rekor-kind.yaml
+++ b/.github/workflows/fulcio-rekor-kind.yaml
@@ -56,7 +56,7 @@ jobs:
         check-latest: true
 
     - name: Check out our repo
-      uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       with:
         path: ./src/github.com/sigstore/scaffolding
 
@@ -179,7 +179,7 @@ jobs:
     # Test with cosign in 'airgapped mode'
     # Uncomment these once modified cosign goes in.
     #- name: Checkout modified cosign for testing.
-    #  uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+    #  uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
     #  with:
     #    repository: vaikas/cosign
     #    ref: air-gap
@@ -201,7 +201,7 @@ jobs:
     #    ./cosign verify --rekor-url ${{ env.REKOR_URL }} --allow-insecure-registry ${{ env.demoimage }}
 
     - name: Checkout TSA for testing.
-      uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       with:
         repository: sigstore/timestamp-authority
         path: ./src/github.com/sigstore/timestamp-authority
diff --git a/.github/workflows/prober-test.yml b/.github/workflows/prober-test.yml
index 241f57392..9a4a6bb75 100644
--- a/.github/workflows/prober-test.yml
+++ b/.github/workflows/prober-test.yml
@@ -20,7 +20,7 @@ jobs:
       contents: read
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
 
       - name: Set up Go
         uses: actions/setup-go@93397bea11091df50f3d7e59dc26a7711a8bcfbe # v4.1.0
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index d9537a6a5..3b4d0d9a1 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -44,7 +44,7 @@ jobs:
         password: ${{ secrets.GITHUB_TOKEN }}
 
     - name: Check out code onto GOPATH
-      uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       with:
         fetch-depth: 1
         path: ./src/github.com/${{ github.repository }}
diff --git a/.github/workflows/terraform.yml b/.github/workflows/terraform.yml
index e72077ab7..b95b39b3c 100644
--- a/.github/workflows/terraform.yml
+++ b/.github/workflows/terraform.yml
@@ -21,7 +21,7 @@ jobs:
 
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
 
       - uses: hashicorp/setup-terraform@633666f66e0061ca3b725c73b2ec20cd13a8fdd1 # v2.0.0
         with:
@@ -41,7 +41,7 @@ jobs:
 
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
 
       - uses: hashicorp/setup-terraform@633666f66e0061ca3b725c73b2ec20cd13a8fdd1 # v2.0.0
         with:
@@ -70,7 +70,7 @@ jobs:
 
     steps:
       - name: 'Checkout'
-        uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+        uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
 
       - name: tfsec
         uses: tfsec/tfsec-sarif-action@21ded20e8ca120cd9d3d6ab04ef746477542a608 # v0.1.0
diff --git a/.github/workflows/test-action-tuf.yaml b/.github/workflows/test-action-tuf.yaml
index ed533ab35..200015887 100644
--- a/.github/workflows/test-action-tuf.yaml
+++ b/.github/workflows/test-action-tuf.yaml
@@ -40,7 +40,7 @@ jobs:
 
     steps:
     - name: Checkout the current action
-      uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
     - name: Test running the action
       uses: ./actions/setup
       with:
@@ -90,7 +90,7 @@ jobs:
         --certificate-oidc-issuer "https://kubernetes.default.svc.cluster.local"
 
     - name: Checkout TSA for testing.
-      uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       with:
         repository: sigstore/timestamp-authority
         path: ./src/github.com/sigstore/timestamp-authority
diff --git a/.github/workflows/test-release.yaml b/.github/workflows/test-release.yaml
index 820f0b300..01c87d1e1 100644
--- a/.github/workflows/test-release.yaml
+++ b/.github/workflows/test-release.yaml
@@ -141,7 +141,7 @@ jobs:
         --certificate-oidc-issuer "https://kubernetes.default.svc.cluster.local"
 
     - name: Checkout TSA for testing.
-      uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       with:
         repository: sigstore/timestamp-authority
         path: ./src/github.com/sigstore/timestamp-authority
diff --git a/.github/workflows/verify.yml b/.github/workflows/verify.yml
index 67c5532bf..04b9ee765 100644
--- a/.github/workflows/verify.yml
+++ b/.github/workflows/verify.yml
@@ -13,7 +13,7 @@ jobs:
     name: license boilerplate check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       - uses: actions/setup-go@93397bea11091df50f3d7e59dc26a7711a8bcfbe # v4.1.0
         with:
           go-version: '1.20'
@@ -30,7 +30,7 @@ jobs:
     name: Shellcheck
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       - name: Run ShellCheck
         uses: ludeeus/action-shellcheck@00cae500b08a931fb5698e11e79bfbd38e612a38 # v2.0.0
 
@@ -38,7 +38,7 @@ jobs:
     name: lint
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@f43a0e5ff2bd294095638e18286ca9a3d1956744 # v3.6.0
+      - uses: actions/checkout@3df4ab11eba7bda6032a0b82a6bb43b11571feac # v4.0.0
       - uses: actions/setup-go@93397bea11091df50f3d7e59dc26a7711a8bcfbe # v4.1.0
         with:
           go-version: '1.20'