diff --git a/.github/workflows/build-metrics-container.yml b/.github/workflows/build-metrics-container.yml
index 751ab679411dc..7924779fc3f8d 100644
--- a/.github/workflows/build-metrics-container.yml
+++ b/.github/workflows/build-metrics-container.yml
@@ -27,7 +27,7 @@ jobs:
       container-filename: ${{ steps.vars.outputs.container-filename }}
     steps:
       - name: Checkout LLVM
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           sparse-checkout: .ci/metrics/
       - name: Write Variables
@@ -49,7 +49,7 @@ jobs:
         run: |
           podman save  ${{ steps.vars.outputs.container-name-tag }} >  ${{ steps.vars.outputs.container-filename }}
       - name: Upload Container Image
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@65c4c4a1ddee5b72f698fdd19549f0f0fb45cf08 # v4.6.0
         with:
           name: container
           path: ${{ steps.vars.outputs.container-filename }}
@@ -66,7 +66,7 @@ jobs:
       GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
       - name: Download Container
-        uses: actions/download-artifact@v4
+        uses: actions/download-artifact@fa0a91b85d4f404e444e00e005971372dc801d16 # v4.1.8
         with:
           name: container
       - name: Push Container
diff --git a/.github/workflows/ci-post-commit-analyzer.yml b/.github/workflows/ci-post-commit-analyzer.yml
index d614dd07b3a49..e0d30b66f66b6 100644
--- a/.github/workflows/ci-post-commit-analyzer.yml
+++ b/.github/workflows/ci-post-commit-analyzer.yml
@@ -44,7 +44,7 @@ jobs:
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
       - name: Setup ccache
-        uses: hendrikmuhs/ccache-action@v1
+        uses: hendrikmuhs/ccache-action@a1209f81afb8c005c13b4296c32e363431bffea5 # v1.2.17
         with:
           # A full build of llvm, clang, lld, and lldb takes about 250MB
           # of ccache space. There's not much reason to have more than this,
diff --git a/.github/workflows/commit-access-review.yml b/.github/workflows/commit-access-review.yml
index f9195a1863dee..5ab0ddd50d241 100644
--- a/.github/workflows/commit-access-review.yml
+++ b/.github/workflows/commit-access-review.yml
@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-22.04
     steps:
       - name: Fetch LLVM sources
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       
       - name: Install dependencies
         run: |
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index b4fa27203236a..3561344bf87c2 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -60,12 +60,12 @@ jobs:
       # a local checkout beforehand.
       - name: Fetch LLVM sources (Push)
         if: ${{ github.event_name == 'push' }}
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 1
       - name: Get subprojects that have doc changes
         id: docs-changed-subprojects
-        uses: tj-actions/changed-files@v39
+        uses: tj-actions/changed-files@fea790cb660e33aef4bdf07304e28fedd77dfa13 # v39.2.4
         with:
           files_yaml: |
             llvm:
@@ -98,11 +98,11 @@ jobs:
               - '.github/workflows/docs.yml'
       - name: Fetch LLVM sources (PR)
         if: ${{ github.event_name == 'pull_request' }}
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 1
       - name: Setup Python env
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           python-version: '3.11'
           cache: 'pip'
@@ -216,7 +216,7 @@ jobs:
           mkdir built-docs/flang
           cp -r flang-build/docs/* built-docs/flang/
       - name: Upload docs
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@65c4c4a1ddee5b72f698fdd19549f0f0fb45cf08 # v4.6.0
         with:
           name: docs-output
           path: built-docs/
diff --git a/.github/workflows/email-check.yaml b/.github/workflows/email-check.yaml
index 8f32d020975f5..5719203c5f908 100644
--- a/.github/workflows/email-check.yaml
+++ b/.github/workflows/email-check.yaml
@@ -14,7 +14,7 @@ jobs:
     if: github.repository == 'llvm/llvm-project'
     steps:
       - name: Fetch LLVM sources
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           ref: ${{ github.event.pull_request.head.sha }}
 
diff --git a/.github/workflows/issue-release-workflow.yml b/.github/workflows/issue-release-workflow.yml
index 5027d4f3ea6f1..1582d06a97d3f 100644
--- a/.github/workflows/issue-release-workflow.yml
+++ b/.github/workflows/issue-release-workflow.yml
@@ -42,7 +42,7 @@ jobs:
       contains(github.event.action == 'opened' && github.event.issue.body || github.event.comment.body, '/cherry-pick')
     steps:
       - name: Fetch LLVM sources
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           repository: llvm/llvm-project
           # GitHub stores the token used for checkout and uses it for pushes
diff --git a/.github/workflows/issue-subscriber.yml b/.github/workflows/issue-subscriber.yml
index ef4fdf4418193..2fb8ad18eb0ac 100644
--- a/.github/workflows/issue-subscriber.yml
+++ b/.github/workflows/issue-subscriber.yml
@@ -14,7 +14,7 @@ jobs:
     if: github.repository == 'llvm/llvm-project'
     steps:
       - name: Checkout Automation Script
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           sparse-checkout: llvm/utils/git/
           ref: main
diff --git a/.github/workflows/issue-write.yml b/.github/workflows/issue-write.yml
index 5334157a7fd20..712c7d8268239 100644
--- a/.github/workflows/issue-write.yml
+++ b/.github/workflows/issue-write.yml
@@ -25,7 +25,7 @@ jobs:
       )
     steps:
       - name: Fetch Sources
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           sparse-checkout: |
             .github/workflows/unprivileged-download-artifact/action.yml
@@ -39,7 +39,7 @@ jobs:
 
       - name: 'Comment on PR'
         if: steps.download-artifact.outputs.artifact-id != ''
-        uses: actions/github-script@v3
+        uses: actions/github-script@ffc2c79a5b2490bd33e0a41c1de74b877714d736 # v3.2.0
         with:
           github-token: ${{ secrets.GITHUB_TOKEN }}
           script: |
diff --git a/.github/workflows/libclang-abi-tests.yml b/.github/workflows/libclang-abi-tests.yml
index 41b3075288d2d..8995d52b9925f 100644
--- a/.github/workflows/libclang-abi-tests.yml
+++ b/.github/workflows/libclang-abi-tests.yml
@@ -38,7 +38,7 @@ jobs:
       LLVM_VERSION_PATCH: ${{ steps.version.outputs.patch }}
     steps:
       - name: Checkout source
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 250
 
diff --git a/.github/workflows/llvm-bugs.yml b/.github/workflows/llvm-bugs.yml
index c392078fa4525..a54e52456e860 100644
--- a/.github/workflows/llvm-bugs.yml
+++ b/.github/workflows/llvm-bugs.yml
@@ -14,13 +14,13 @@ jobs:
     runs-on: ubuntu-latest
     if: github.repository == 'llvm/llvm-project'
     steps:
-      - uses: actions/setup-node@v4
+      - uses: actions/setup-node@1d0ff469b7ec7b3cb9d8673fde0c81c44821de2a # v4.2.0
         with:
           node-version: 18
           check-latest: true
       - run: npm install mailgun.js form-data
       - name: Send notification
-        uses: actions/github-script@v6
+        uses: actions/github-script@d7906e4ad0b1822421a7e6a35d5ca353c962f410 # v6.4.1
         env:
           MAILGUN_API_KEY: ${{ secrets.LLVM_BUGS_KEY }}
         with:
diff --git a/.github/workflows/llvm-project-tests.yml b/.github/workflows/llvm-project-tests.yml
index 4ff84c511250f..d857995d325d0 100644
--- a/.github/workflows/llvm-project-tests.yml
+++ b/.github/workflows/llvm-project-tests.yml
@@ -82,7 +82,7 @@ jobs:
       # lldb.  Using this setup-python action to make 3.10 the default
       # python fixes this.
       - name: Setup Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           python-version: ${{ inputs.python_version }}
       - name: Install Ninja
@@ -91,11 +91,11 @@ jobs:
       # actions/checkout deletes any existing files in the new git directory,
       # so this needs to either run before ccache-action or it has to use
       # clean: false.
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 250
       - name: Setup ccache
-        uses: hendrikmuhs/ccache-action@v1
+        uses: hendrikmuhs/ccache-action@a1209f81afb8c005c13b4296c32e363431bffea5 # v1.2.17
         with:
           # A full build of llvm, clang, lld, and lldb takes about 250MB
           # of ccache space. There's not much reason to have more than this,
diff --git a/.github/workflows/llvm-tests.yml b/.github/workflows/llvm-tests.yml
index 9b3d49d4e99b9..2c41368369ce8 100644
--- a/.github/workflows/llvm-tests.yml
+++ b/.github/workflows/llvm-tests.yml
@@ -38,7 +38,7 @@ jobs:
       LLVM_VERSION_PATCH: ${{ steps.version.outputs.patch }}
     steps:
       - name: Checkout source
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 250
 
diff --git a/.github/workflows/merged-prs.yml b/.github/workflows/merged-prs.yml
index e29afd4097f9f..aa559e4b75a76 100644
--- a/.github/workflows/merged-prs.yml
+++ b/.github/workflows/merged-prs.yml
@@ -21,7 +21,7 @@ jobs:
       (github.event.pull_request.merged == true)
     steps:
       - name: Checkout Automation Script
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           sparse-checkout: llvm/utils/git/
           ref: main
diff --git a/.github/workflows/new-prs.yml b/.github/workflows/new-prs.yml
index 88175d6f8d64d..3f042e7616011 100644
--- a/.github/workflows/new-prs.yml
+++ b/.github/workflows/new-prs.yml
@@ -35,7 +35,7 @@ jobs:
       (github.event.pull_request.author_association != 'OWNER')
     steps:
       - name: Checkout Automation Script
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           sparse-checkout: llvm/utils/git/
           ref: main
@@ -67,7 +67,7 @@ jobs:
       github.event.pull_request.draft == false &&
       github.event.pull_request.commits < 10
     steps:
-      - uses: actions/labeler@v4
+      - uses: actions/labeler@ac9175f8a1f3625fd0d4fb234536d26811351594 # v4.3.0
         with:
           configuration-path: .github/new-prs-labeler.yml
           # workaround for https://github.com/actions/labeler/issues/112
diff --git a/.github/workflows/pr-code-format.yml b/.github/workflows/pr-code-format.yml
index 0e6180acf4a46..a5a5626369bdb 100644
--- a/.github/workflows/pr-code-format.yml
+++ b/.github/workflows/pr-code-format.yml
@@ -19,12 +19,12 @@ jobs:
     if: github.repository == 'llvm/llvm-project'
     steps:
       - name: Fetch LLVM sources
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           ref: ${{ github.event.pull_request.head.sha }}
 
       - name: Checkout through merge base
-        uses: rmacklin/fetch-through-merge-base@v0
+        uses: rmacklin/fetch-through-merge-base@bfe4d03a86f9afa52bc1a70e9814fc92a07f7b75 # v0.3.0
         with:
           base_ref: ${{ github.event.pull_request.base.ref }}
           head_ref: ${{ github.event.pull_request.head.sha }}
@@ -32,7 +32,7 @@ jobs:
 
       - name: Get changed files
         id: changed-files
-        uses: tj-actions/changed-files@v39
+        uses: tj-actions/changed-files@fea790cb660e33aef4bdf07304e28fedd77dfa13 # v39.2.4
         with:
           separator: ","
           skip_initial_fetch: true
@@ -40,7 +40,7 @@ jobs:
       # We need to pull the script from the main branch, so that we ensure
       # we get the latest version of this script.
       - name: Fetch code formatting utils
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           repository: ${{ github.repository }}
           ref: ${{ github.base_ref }}
@@ -58,12 +58,12 @@ jobs:
           echo "$CHANGED_FILES"
 
       - name: Install clang-format
-        uses: aminya/setup-cpp@v1
+        uses: aminya/setup-cpp@17c11551771948abc5752bbf3183482567c7caf0 # v1.1.1
         with:
           clangformat: 19.1.6
 
       - name: Setup Python env
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           python-version: '3.11'
           cache: 'pip'
diff --git a/.github/workflows/pr-subscriber.yml b/.github/workflows/pr-subscriber.yml
index 272d3e2f9ef8a..0e3d3e04ee938 100644
--- a/.github/workflows/pr-subscriber.yml
+++ b/.github/workflows/pr-subscriber.yml
@@ -14,7 +14,7 @@ jobs:
     if: github.repository == 'llvm/llvm-project'
     steps:
       - name: Checkout Automation Script
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           sparse-checkout: llvm/utils/git/
           ref: main
diff --git a/.github/workflows/release-binaries.yml b/.github/workflows/release-binaries.yml
index 231dd26e54ae0..fd6a6cc931ec4 100644
--- a/.github/workflows/release-binaries.yml
+++ b/.github/workflows/release-binaries.yml
@@ -336,7 +336,7 @@ jobs:
     runs-on: ${{ needs.prepare.outputs.test-runs-on }}
     steps:
     - name: Checkout Actions
-      uses: actions/checkout@v4
+      uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
       with:
         ref: ${{ (github.event_name == 'pull_request' && github.sha) || 'main' }}
         sparse-checkout: |
diff --git a/.github/workflows/release-documentation.yml b/.github/workflows/release-documentation.yml
index 09e21585bfc56..bac500080f90a 100644
--- a/.github/workflows/release-documentation.yml
+++ b/.github/workflows/release-documentation.yml
@@ -37,7 +37,7 @@ jobs:
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
       - name: Setup Python env
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           cache: 'pip'
           cache-dependency-path: './llvm/docs/requirements.txt'
diff --git a/.github/workflows/release-doxygen.yml b/.github/workflows/release-doxygen.yml
index ea95e5bb12b2b..17d437e3a649d 100644
--- a/.github/workflows/release-doxygen.yml
+++ b/.github/workflows/release-doxygen.yml
@@ -43,7 +43,7 @@ jobs:
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1
 
       - name: Setup Python env
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@42375524e23c412d93fb67b49958b491fce71c38 # v5.4.0
         with:
           cache: 'pip'
           cache-dependency-path: './llvm/docs/requirements.txt'
diff --git a/.github/workflows/release-lit.yml b/.github/workflows/release-lit.yml
index 9d6f3140e6883..346cf3bf2c460 100644
--- a/.github/workflows/release-lit.yml
+++ b/.github/workflows/release-lit.yml
@@ -45,7 +45,7 @@ jobs:
           ./llvm/utils/release/./github-upload-release.py --token "$GITHUB_TOKEN" --user ${{ github.actor }} --user-token "$USER_TOKEN" check-permissions
 
       - name: Setup Cpp
-        uses: aminya/setup-cpp@v1
+        uses: aminya/setup-cpp@17c11551771948abc5752bbf3183482567c7caf0 # v1.1.1
         with:
           compiler: llvm-16.0.6
           cmake: true
@@ -66,14 +66,14 @@ jobs:
           python3 setup.py sdist bdist_wheel
 
       - name: Upload lit to test.pypi.org
-        uses: pypa/gh-action-pypi-publish@release/v1
+        uses: pypa/gh-action-pypi-publish@76f52bc884231f62b9a034ebfe128415bbaabdfc # v1.12.4
         with:
           password: ${{ secrets.LLVM_LIT_TEST_PYPI_API_TOKEN }}
           repository-url: https://test.pypi.org/legacy/
           packages-dir: llvm/utils/lit/dist/
 
       - name: Upload lit to pypi.org
-        uses: pypa/gh-action-pypi-publish@release/v1
+        uses: pypa/gh-action-pypi-publish@76f52bc884231f62b9a034ebfe128415bbaabdfc # v1.12.4
         with:
           password: ${{ secrets.LLVM_LIT_PYPI_API_TOKEN }}
           packages-dir: llvm/utils/lit/dist/
diff --git a/.github/workflows/version-check.yml b/.github/workflows/version-check.yml
index 894e07d323ca9..18e21a1a8f295 100644
--- a/.github/workflows/version-check.yml
+++ b/.github/workflows/version-check.yml
@@ -17,7 +17,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Fetch LLVM sources
-        uses: actions/checkout@v4
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
         with:
           fetch-depth: 0