diff --git a/.github/workflows/pr.yaml b/.github/workflows/pr.yaml
index 795348d..bf8346e 100644
--- a/.github/workflows/pr.yaml
+++ b/.github/workflows/pr.yaml
@@ -101,7 +101,7 @@ jobs:
 
       - name: Upload artifacts on failure
         if: failure()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: quick-regression-failure-${{ matrix.system }}
           path: |
@@ -135,7 +135,7 @@ jobs:
 
       - name: Upload docs artifact
         if: always()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: docs-html
           path: docs/_build/html
diff --git a/.github/workflows/release.yaml b/.github/workflows/release.yaml
index 9ccde59..9a48aae 100644
--- a/.github/workflows/release.yaml
+++ b/.github/workflows/release.yaml
@@ -154,7 +154,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@11d5960a326750d5838078e36cf38b85af677262 # v4
         with:
           ref: main
 
@@ -164,7 +164,7 @@ jobs:
           grep '{% set version' conda-recipe/meta.yaml
 
       - name: Setup Conda (conda-forge only)
-        uses: conda-incubator/setup-miniconda@v3
+        uses: conda-incubator/setup-miniconda@fc2d68f6413eb2d87b895e92f8584b5b94a10167 # v3
         with:
           miniforge-variant: Miniforge3
           python-version: "3.12"
diff --git a/.github/workflows/update-copyright-years-in-license-file.yaml b/.github/workflows/update-copyright-years-in-license-file.yaml
index 4856a7d..96d04a3 100644
--- a/.github/workflows/update-copyright-years-in-license-file.yaml
+++ b/.github/workflows/update-copyright-years-in-license-file.yaml
@@ -9,9 +9,9 @@ jobs:
     update-license-year:
         runs-on: ubuntu-latest
         steps:
-            - uses: actions/checkout@v6
+            - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6
               with:
                   fetch-depth: 0
-            - uses: FantasticFiasco/action-update-license-year@v3
+            - uses: FantasticFiasco/action-update-license-year@f180e962fa988db222d8f03ef4636750312d1b3d # v3
               with:
                   token: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/weekly-docs.yaml b/.github/workflows/weekly-docs.yaml
index b0e3259..daf9a16 100644
--- a/.github/workflows/weekly-docs.yaml
+++ b/.github/workflows/weekly-docs.yaml
@@ -41,7 +41,7 @@ jobs:
 
       - name: Upload docs artifacts on failure
         if: failure()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: docs-${{ matrix.os }}-py${{ matrix.python-version }}-failure
           path: |
diff --git a/.github/workflows/weekly-regression.yaml b/.github/workflows/weekly-regression.yaml
index 16d152d..4e62823 100644
--- a/.github/workflows/weekly-regression.yaml
+++ b/.github/workflows/weekly-regression.yaml
@@ -74,7 +74,7 @@ jobs:
 
       - name: Upload regression artifacts (failure)
         if: failure()
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@ea165f8d65b6e75b540449e92b4886f43607fa02 # v4
         with:
           name: regression-${{ matrix.system }}-artifacts
           path: |