diff --git a/.github/workflows/cleanup.yml b/.github/workflows/cleanup.yml
index 50ff872f..85da31d6 100644
--- a/.github/workflows/cleanup.yml
+++ b/.github/workflows/cleanup.yml
@@ -13,12 +13,12 @@ jobs:
       pull-requests: write
     steps:
       - name: Checkout Repository
-        uses: actions/checkout@v4
+        uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
         with:
           ref: ${{ github.event.pull_request.head.ref }}
           fetch-depth: 0
       - name: Setup Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: 3.11
       - name: Install Dependencies
diff --git a/.github/workflows/marimo_export_md.yml b/.github/workflows/marimo_export_md.yml
index 130601ec..b979c38e 100644
--- a/.github/workflows/marimo_export_md.yml
+++ b/.github/workflows/marimo_export_md.yml
@@ -38,12 +38,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout branch
-        uses: actions/checkout@v4
+        uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
         with:
           ref: ${{ github.ref_name }}
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: "3.11"
 
diff --git a/.github/workflows/marimo_molab.yml b/.github/workflows/marimo_molab.yml
index d9dbb3e9..a8135fbc 100644
--- a/.github/workflows/marimo_molab.yml
+++ b/.github/workflows/marimo_molab.yml
@@ -26,7 +26,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Comment molab links for modified marimo notebooks
-        uses: actions/github-script@v7
+        uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # v7
         with:
           script: |
             const pr = context.payload.pull_request;
diff --git a/.github/workflows/pr_reply1.yml b/.github/workflows/pr_reply1.yml
index 93debf68..43143f73 100644
--- a/.github/workflows/pr_reply1.yml
+++ b/.github/workflows/pr_reply1.yml
@@ -10,10 +10,10 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@a37ce9120846195fa4ece8f58b268e6043cb2f26 # v3
       with:
         fetch-depth: 0
-    - uses: actions/setup-python@v3
+    - uses: actions/setup-python@3542bca2639a428e1796aaa6a2ffef0c0f575566 # v3
       with:
         python-version: 3.9
     - name: Run script
@@ -22,7 +22,7 @@ jobs:
       run: |
         pip install -Uq ghapi nb_helpers
         python .github/scripts/pr_reply1.py
-    - uses: actions/upload-artifact@v4
+    - uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
       with:
         name: pr_comment
         path: modified_colabs.json
\ No newline at end of file
diff --git a/.github/workflows/pr_reply2.yml b/.github/workflows/pr_reply2.yml
index 558077eb..97001805 100644
--- a/.github/workflows/pr_reply2.yml
+++ b/.github/workflows/pr_reply2.yml
@@ -13,10 +13,10 @@ jobs:
   download_payload:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@a37ce9120846195fa4ece8f58b268e6043cb2f26 # v3
       with:
         fetch-depth: 0
-    - uses: actions/setup-python@v3
+    - uses: actions/setup-python@3542bca2639a428e1796aaa6a2ffef0c0f575566 # v3
       with:
         python-version: 3.9
     - name: Run script