diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 9615c513dd67da..87091022c29303 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -32,7 +32,7 @@ jobs:
       run_ssl_tests: ${{ steps.check.outputs.run_ssl_tests }}
       config_hash: ${{ steps.config_hash.outputs.hash }}
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Check for source changes
         id: check
         run: |
@@ -64,7 +64,7 @@ jobs:
       - name: Get a list of the changed documentation-related files
         if: github.event_name == 'pull_request'
         id: changed-docs-files
-        uses: Ana06/get-changed-files@v2.3.0
+        uses: Ana06/get-changed-files@25f79e676e7ea1868813e21465014798211fad8c # v2.3.0
         with:
           filter: |
             Doc/**
@@ -91,10 +91,10 @@ jobs:
     needs: check_source
     if: needs.check_source.outputs.run_tests == 'true'
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           persist-credentials: false
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
       - name: Install dependencies
         run: |
             sudo ./.github/workflows/posix-deps-apt.sh
@@ -123,7 +123,7 @@ jobs:
         if: ${{ failure() && steps.check.conclusion == 'failure' }}
         run: |
           make regen-abidump
-      - uses: actions/upload-artifact@v6
+      - uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
         name: Publish updated ABI files
         if: ${{ failure() && steps.check.conclusion == 'failure' }}
         with:
@@ -139,16 +139,16 @@ jobs:
     needs: check_source
     if: needs.check_source.outputs.run_tests == 'true'
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           persist-credentials: false
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: '3.x'
       - name: Runner image version
         run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
       - name: Restore config.cache
-        uses: actions/cache@v5
+        uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
         with:
           path: config.cache
           # Include env.pythonLocation in key to avoid changes in environment when setup-python updates Python
@@ -158,7 +158,7 @@ jobs:
       - name: Add ccache to PATH
         run: echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
       - name: Configure ccache action
-        uses: hendrikmuhs/ccache-action@v1.2
+        uses: hendrikmuhs/ccache-action@5ebbd400eff9e74630f759d94ddd7b6c26299639 # v1.2.20
         with:
           save: false
       - name: Check Autoconf version 2.69 and aclocal 1.16.3
@@ -243,13 +243,13 @@ jobs:
       OPENSSL_DIR: ${{ github.workspace }}/multissl/openssl/${{ matrix.openssl_ver }}
       LD_LIBRARY_PATH: ${{ github.workspace }}/multissl/openssl/${{ matrix.openssl_ver }}/lib
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       with:
         persist-credentials: false
     - name: Runner image version
       run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
     - name: Restore config.cache
-      uses: actions/cache@v5
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: config.cache
         key: ${{ github.job }}-${{ env.IMAGE_OS_VERSION }}-${{ needs.check_source.outputs.config_hash }}
@@ -264,7 +264,7 @@ jobs:
         echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> "$GITHUB_ENV"
     - name: 'Restore OpenSSL build'
       id: cache-openssl
-      uses: actions/cache@v5
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: ./multissl/openssl/${{ env.OPENSSL_VER }}
         key: ${{ matrix.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
@@ -275,7 +275,7 @@ jobs:
       run: |
         echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
     - name: Configure ccache action
-      uses: hendrikmuhs/ccache-action@v1.2
+      uses: hendrikmuhs/ccache-action@5ebbd400eff9e74630f759d94ddd7b6c26299639 # v1.2.20
       with:
         save: false
     - name: Configure CPython
@@ -298,13 +298,13 @@ jobs:
       PYTHONSTRICTEXTENSIONBUILD: 1
       ASAN_OPTIONS: detect_leaks=0:allocator_may_return_null=1:handle_segv=0
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       with:
         persist-credentials: false
     - name: Runner image version
       run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
     - name: Restore config.cache
-      uses: actions/cache@v5
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: config.cache
         key: ${{ github.job }}-${{ env.IMAGE_OS_VERSION }}-${{ needs.check_source.outputs.config_hash }}
@@ -313,7 +313,7 @@ jobs:
     - name: Install dependencies
       run: sudo ./.github/workflows/posix-deps-apt.sh
     - name: Set up GCC-10 for ASAN
-      uses: egor-tensin/setup-gcc@v2
+      uses: egor-tensin/setup-gcc@a2861a8b8538f49cf2850980acccf6b05a1b2ae4 # v2.0
       with:
         version: 10
     - name: Configure OpenSSL env vars
@@ -323,7 +323,7 @@ jobs:
         echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> "$GITHUB_ENV"
     - name: 'Restore OpenSSL build'
       id: cache-openssl
-      uses: actions/cache@v5
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: ./multissl/openssl/${{ env.OPENSSL_VER }}
         key: ${{ matrix.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
@@ -334,7 +334,7 @@ jobs:
       run: |
         echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
     - name: Configure ccache action
-      uses: hendrikmuhs/ccache-action@v1.2
+      uses: hendrikmuhs/ccache-action@5ebbd400eff9e74630f759d94ddd7b6c26299639 # v1.2.20
       with:
         save: ${{ github.event_name == 'push' }}
         max-size: "200M"
diff --git a/.github/workflows/build_msi.yml b/.github/workflows/build_msi.yml
index 505c3858348af8..73190e4379b233 100644
--- a/.github/workflows/build_msi.yml
+++ b/.github/workflows/build_msi.yml
@@ -36,7 +36,7 @@ jobs:
     runs-on: windows-2022
     timeout-minutes: 60
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: Build CPython installer
       run: .\Tools\msi\build.bat -x86
 
@@ -45,7 +45,7 @@ jobs:
     runs-on: windows-2022
     timeout-minutes: 60
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: Build CPython installer
       run: .\Tools\msi\build.bat -x64
 
@@ -54,6 +54,6 @@ jobs:
     runs-on: windows-2022
     timeout-minutes: 60
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: Build CPython installer
       run: .\Tools\msi\build.bat -arm64
diff --git a/.github/workflows/documentation-links.yml b/.github/workflows/documentation-links.yml
index 43a7afec73884e..e35c0182ff4024 100644
--- a/.github/workflows/documentation-links.yml
+++ b/.github/workflows/documentation-links.yml
@@ -21,7 +21,7 @@ jobs:
   documentation-links:
     runs-on: ubuntu-latest
     steps:
-      - uses: readthedocs/actions/preview@v1
+      - uses: readthedocs/actions/preview@b8bba1484329bda1a3abe986df7ebc80a8950333 # v1.5
         with:
           project-slug: "cpython-previews"
           single-version: "true"
diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index 9fc8b37e440b9e..20d1477e508468 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -19,8 +19,8 @@ jobs:
     timeout-minutes: 10
 
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: "3.x"
-      - uses: pre-commit/action@v3.0.1
+      - uses: pre-commit/action@2c7b3805fd2a0fd8c1884dcaebf91fc102a13ecd # v3.0.1
diff --git a/.github/workflows/new-bugs-announce-notifier.yml b/.github/workflows/new-bugs-announce-notifier.yml
index d9b9db4d52d941..69cf113f8f00d5 100644
--- a/.github/workflows/new-bugs-announce-notifier.yml
+++ b/.github/workflows/new-bugs-announce-notifier.yml
@@ -13,12 +13,12 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/setup-node@v6
+      - uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
         with:
           node-version: 14
       - run: npm install mailgun.js form-data
       - name: Send notification
-        uses: actions/github-script@v8
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         env:
           MAILGUN_API_KEY: ${{ secrets.PSF_MAILGUN_KEY }}
         with:
diff --git a/.github/workflows/require-pr-label.yml b/.github/workflows/require-pr-label.yml
index ff5cbdf3eda749..5af45789226278 100644
--- a/.github/workflows/require-pr-label.yml
+++ b/.github/workflows/require-pr-label.yml
@@ -16,7 +16,7 @@ jobs:
     timeout-minutes: 10
 
     steps:
-      - uses: mheap/github-action-required-labels@v5
+      - uses: mheap/github-action-required-labels@0ac283b4e65c1fb28ce6079dea5546ceca98ccbe # v5.5.2
         with:
           mode: exactly
           count: 0
diff --git a/.github/workflows/reusable-docs.yml b/.github/workflows/reusable-docs.yml
index c9372d09124d29..e99cc1fa5f217d 100644
--- a/.github/workflows/reusable-docs.yml
+++ b/.github/workflows/reusable-docs.yml
@@ -17,9 +17,9 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 60
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: 'Set up Python'
-      uses: actions/setup-python@v6
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
       with:
         python-version: '3'
         cache: 'pip'
@@ -29,7 +29,7 @@ jobs:
     - name: 'Build HTML documentation'
       run: make -C Doc/ SPHINXOPTS="-q" SPHINXERRORHANDLING="-W --keep-going" html
     - name: 'Upload'
-      uses: actions/upload-artifact@v6
+      uses: actions/upload-artifact@b7c566a772e6b6bfb58ed0dc250532a479d7789f # v6.0.0
       with:
         name: doc-html
         path: Doc/build/html
@@ -40,9 +40,9 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 60
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: 'Set up Python'
-      uses: actions/setup-python@v6
+      uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
       with:
         python-version: '3.11'  # known to work with Sphinx 4.2
         cache: 'pip'
@@ -58,8 +58,8 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 60
     steps:
-    - uses: actions/checkout@v6
-    - uses: actions/cache@v5
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+    - uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: ~/.cache/pip
         key: ubuntu-doc-${{ hashFiles('Doc/requirements.txt') }}
diff --git a/.github/workflows/reusable-macos.yml b/.github/workflows/reusable-macos.yml
index aa0f4f3a332ee9..c4cbe180430f16 100644
--- a/.github/workflows/reusable-macos.yml
+++ b/.github/workflows/reusable-macos.yml
@@ -28,11 +28,11 @@ jobs:
         ]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: Runner image version
       run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
     - name: Restore config.cache
-      uses: actions/cache@v5
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: config.cache
         key: ${{ github.job }}-${{ env.IMAGE_OS_VERSION }}-${{ inputs.config_hash }}
diff --git a/.github/workflows/reusable-ubuntu.yml b/.github/workflows/reusable-ubuntu.yml
index 9ec9888269e645..bc62521b6b914b 100644
--- a/.github/workflows/reusable-ubuntu.yml
+++ b/.github/workflows/reusable-ubuntu.yml
@@ -24,7 +24,7 @@ jobs:
       OPENSSL_VER: 3.0.15
       PYTHONSTRICTEXTENSIONBUILD: 1
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       with:
         persist-credentials: false
     - name: Register gcc problem matcher
@@ -38,7 +38,7 @@ jobs:
         echo "LD_LIBRARY_PATH=${GITHUB_WORKSPACE}/multissl/openssl/${OPENSSL_VER}/lib" >> "$GITHUB_ENV"
     - name: 'Restore OpenSSL build'
       id: cache-openssl
-      uses: actions/cache@v5
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: ./multissl/openssl/${{ env.OPENSSL_VER }}
         key: ${{ matrix.os }}-multissl-openssl-${{ env.OPENSSL_VER }}
@@ -49,7 +49,7 @@ jobs:
       run: |
         echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
     - name: Configure ccache action
-      uses: hendrikmuhs/ccache-action@v1.2
+      uses: hendrikmuhs/ccache-action@5ebbd400eff9e74630f759d94ddd7b6c26299639 # v1.2.20
       with:
         save: ${{ github.event_name == 'push' }}
         max-size: "200M"
@@ -64,7 +64,7 @@ jobs:
     - name: Runner image version
       run: echo "IMAGE_OS_VERSION=${ImageOS}-${ImageVersion}" >> "$GITHUB_ENV"
     - name: Restore config.cache
-      uses: actions/cache@v5
+      uses: actions/cache@668228422ae6a00e4ad889ee87cd7109ec5666a7 # v5.0.4
       with:
         path: ${{ env.CPYTHON_BUILDDIR }}/config.cache
         key: ${{ github.job }}-${{ env.IMAGE_OS_VERSION }}-${{ inputs.config_hash }}
diff --git a/.github/workflows/reusable-windows.yml b/.github/workflows/reusable-windows.yml
index 92ff7219f97805..851f501dbf42c4 100644
--- a/.github/workflows/reusable-windows.yml
+++ b/.github/workflows/reusable-windows.yml
@@ -14,7 +14,7 @@ jobs:
     env:
       IncludeUwp: 'true'
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: Build CPython
       run: .\PCbuild\build.bat -e -d -p Win32 ${{ inputs.free-threading && '--disable-gil' || '' }}
     - name: Display build info
@@ -29,7 +29,7 @@ jobs:
     env:
        IncludeUwp: 'true'
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: Register MSVC problem matcher
       run: echo "::add-matcher::.github/problem-matchers/msvc.json"
     - name: Build CPython
@@ -46,7 +46,7 @@ jobs:
     env:
       IncludeUwp: 'true'
     steps:
-    - uses: actions/checkout@v6
+    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
     - name: Register MSVC problem matcher
       run: echo "::add-matcher::.github/problem-matchers/msvc.json"
     - name: Build CPython
diff --git a/.github/workflows/stale.yml b/.github/workflows/stale.yml
index 07608fe91b4dbe..23a316befc6cba 100644
--- a/.github/workflows/stale.yml
+++ b/.github/workflows/stale.yml
@@ -16,7 +16,7 @@ jobs:
 
     steps:
     - name: "Check PRs"
-      uses: actions/stale@v9
+      uses: actions/stale@5bef64f19d7facfb25b37b414482c7164d639639 # v9.1.0
       with:
         repo-token: ${{ secrets.GITHUB_TOKEN }}
         stale-pr-message: 'This PR is stale because it has been open for 30 days with no activity.'
diff --git a/.github/workflows/verify-ensurepip-wheels.yml b/.github/workflows/verify-ensurepip-wheels.yml
index 00bcf3370e0865..2c47fdbc1e12b5 100644
--- a/.github/workflows/verify-ensurepip-wheels.yml
+++ b/.github/workflows/verify-ensurepip-wheels.yml
@@ -25,8 +25,8 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 10
     steps:
-      - uses: actions/checkout@v6
-      - uses: actions/setup-python@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
+      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
         with:
           python-version: '3'
       - name: Compare checksums of bundled pip and setuptools to ones published on PyPI
diff --git a/.github/workflows/verify-expat.yml b/.github/workflows/verify-expat.yml
index 6b12b95cb11ff2..472a11db2da5fb 100644
--- a/.github/workflows/verify-expat.yml
+++ b/.github/workflows/verify-expat.yml
@@ -23,7 +23,7 @@ jobs:
     runs-on: ubuntu-latest
     timeout-minutes: 5
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
         with:
           persist-credentials: false
       - name: Download and verify bundled libexpat files