diff --git a/.github/workflows/release-tags.yml b/.github/workflows/release-tags.yml
index 0e8706e..e1b720b 100644
--- a/.github/workflows/release-tags.yml
+++ b/.github/workflows/release-tags.yml
@@ -19,7 +19,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/validate-release-pr.yml b/.github/workflows/validate-release-pr.yml
index 4716bbd..b4d103b 100644
--- a/.github/workflows/validate-release-pr.yml
+++ b/.github/workflows/validate-release-pr.yml
@@ -13,7 +13,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 15
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6
         with:
           fetch-depth: 0
 
@@ -36,7 +36,7 @@ jobs:
       # rebuild toolchain to match promptfoo's release job (.nvmrc -> Node 24).
       - name: Set up Node.js
         if: ${{ startsWith(github.head_ref, 'release/code-scan-action-v') }}
-        uses: actions/setup-node@v6
+        uses: actions/setup-node@249970729cb0ef3589644e2896645e5dc5ba9c38 # v6
         with:
           node-version: '24'