diff --git a/.github/workflows/acknowledge-new-issues.yml b/.github/workflows/acknowledge-new-issues.yml
index 3d14aeda01d..03f84516abd 100644
--- a/.github/workflows/acknowledge-new-issues.yml
+++ b/.github/workflows/acknowledge-new-issues.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Comment to acknowledge issue
-        uses: peter-evans/create-or-update-comment@v5
+        uses: peter-evans/create-or-update-comment@e8674b075228eee787fea43ef493e45ece1004c9 # v5
         with:
           issue-number: ${{ github.event.issue.number }}
           body: |
diff --git a/.github/workflows/acknowledge-new-prs.yml b/.github/workflows/acknowledge-new-prs.yml
index 1380ce88457..969aba898db 100644
--- a/.github/workflows/acknowledge-new-prs.yml
+++ b/.github/workflows/acknowledge-new-prs.yml
@@ -11,7 +11,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Comment to acknowledge PRs
-        uses: peter-evans/create-or-update-comment@v5
+        uses: peter-evans/create-or-update-comment@e8674b075228eee787fea43ef493e45ece1004c9 # v5
         with:
           issue-number: ${{ github.event.pull_request.number }}
           body: |
diff --git a/.github/workflows/ado-integration.yml b/.github/workflows/ado-integration.yml
index 11a485d71fe..cc033031a98 100644
--- a/.github/workflows/ado-integration.yml
+++ b/.github/workflows/ado-integration.yml
@@ -9,7 +9,7 @@ jobs:
   alert:
     runs-on: ubuntu-latest
     steps:
-      - uses: mhamilton723/github-actions-issue-to-work-item@master
+      - uses: mhamilton723/github-actions-issue-to-work-item@9bd9d44197557fd55cc7043512a84ea7aa4489d3 # master
         env:
           ado_token: "${{ secrets.ADO_PERSONAL_ACCESS_TOKEN }}"
           github_token: "${{ secrets.GH_PERSONAL_ACCESS_TOKEN }}"
diff --git a/.github/workflows/ado-pr-to-workitem.yml b/.github/workflows/ado-pr-to-workitem.yml
index 8a238371423..9e64474bb05 100644
--- a/.github/workflows/ado-pr-to-workitem.yml
+++ b/.github/workflows/ado-pr-to-workitem.yml
@@ -10,7 +10,7 @@ jobs:
   alert:
     runs-on: ubuntu-latest
     steps:
-    - uses: danhellem/github-actions-pr-to-work-item@master
+    - uses: danhellem/github-actions-pr-to-work-item@496254e48adbe7f1ed14a8afb71dc520b2c052ac # master
       env:
         ado_token: '${{ secrets.ADO_PERSONAL_ACCESS_TOKEN }}'
         github_token: '${{ secrets.GH_PERSONAL_ACCESS_TOKEN }}'
diff --git a/.github/workflows/check-dead-links.yml b/.github/workflows/check-dead-links.yml
index 99f30184f14..5d5a08a6362 100644
--- a/.github/workflows/check-dead-links.yml
+++ b/.github/workflows/check-dead-links.yml
@@ -15,7 +15,7 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
       - name: Fetch sitemap URLs
         run: |
@@ -26,7 +26,7 @@ jobs:
           echo "Found $(wc -l < urls.txt) URLs in sitemap"
 
       - name: Scan for dead links
-        uses: lycheeverse/lychee-action@v2
+        uses: lycheeverse/lychee-action@8646ba30535128ac92d33dfc9133794bfdd9b411 # v2
         with:
           args: >-
             --no-progress
diff --git a/.github/workflows/check-semantic-prs.yaml b/.github/workflows/check-semantic-prs.yaml
index cbb5736cd02..711bfdb425f 100644
--- a/.github/workflows/check-semantic-prs.yaml
+++ b/.github/workflows/check-semantic-prs.yaml
@@ -13,6 +13,6 @@ jobs:
     name: Validate PR title
     runs-on: ubuntu-latest
     steps:
-      - uses: amannn/action-semantic-pull-request@v5.4.0
+      - uses: amannn/action-semantic-pull-request@e9fabac35e210fea40ca5b14c0da95a099eff26f # v5.4.0
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
index 616775e96a4..7104cb6d298 100644
--- a/.github/workflows/codeql.yml
+++ b/.github/workflows/codeql.yml
@@ -42,11 +42,11 @@ jobs:
 
     steps:
     - name: Checkout repository
-      uses: actions/checkout@v4
+      uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
     # Initializes the CodeQL tools for scanning.
     - name: Initialize CodeQL
-      uses: github/codeql-action/init@v3
+      uses: github/codeql-action/init@5c8a8a642e79153f5d047b10ec1cba1d1cc65699 # v3
       with:
         languages: ${{ matrix.language }}
         # If you wish to specify custom queries, you can do so here or in a config file.
@@ -60,7 +60,7 @@ jobs:
     # Autobuild attempts to build any compiled languages  (C/C++, C#, Go, or Java).
     # If this step fails, then you should remove it and run the build manually (see below)
     - name: Autobuild
-      uses: github/codeql-action/autobuild@v3
+      uses: github/codeql-action/autobuild@5c8a8a642e79153f5d047b10ec1cba1d1cc65699 # v3
 
     # ℹ️ Command-line programs to run using the OS shell.
     # 📚 See https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#jobsjob_idstepsrun
@@ -73,6 +73,6 @@ jobs:
     #   ./location_of_script_within_repo/buildscript.sh
 
     - name: Perform CodeQL Analysis
-      uses: github/codeql-action/analyze@v3
+      uses: github/codeql-action/analyze@5c8a8a642e79153f5d047b10ec1cba1d1cc65699 # v3
       with:
         category: "/language:${{matrix.language}}"
diff --git a/.github/workflows/dependency-review.yml b/.github/workflows/dependency-review.yml
index af385f8c143..c16fcc109b9 100644
--- a/.github/workflows/dependency-review.yml
+++ b/.github/workflows/dependency-review.yml
@@ -14,10 +14,10 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
       - name: Dependency Review
-        uses: actions/dependency-review-action@v4
+        uses: actions/dependency-review-action@2031cfc080254a8a887f58cffee85186f0e49e48 # v4
         with:
           fail-on-severity: high
           comment-summary-in-pr: always
diff --git a/.github/workflows/pr-validation.yml b/.github/workflows/pr-validation.yml
index 85bfae3c347..0c9c22cf463 100644
--- a/.github/workflows/pr-validation.yml
+++ b/.github/workflows/pr-validation.yml
@@ -12,10 +12,10 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
       - name: Set up Python
-        uses: actions/setup-python@v5
+        uses: actions/setup-python@a26af69be951a213d495a4c3e4e4022e16d87065 # v5
         with:
           python-version: "3.12"
 
@@ -30,10 +30,10 @@ jobs:
 
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
 
       - name: Set up JDK 11
-        uses: actions/setup-java@v4
+        uses: actions/setup-java@c1e323688fd81a25caa38c78aa6df2d33d3e20d9 # v4
         with:
           distribution: temurin
           java-version: 11
diff --git a/.github/workflows/remove-awaiting-response-label.yml b/.github/workflows/remove-awaiting-response-label.yml
index 1ff1e4b94d1..0882e81d16c 100644
--- a/.github/workflows/remove-awaiting-response-label.yml
+++ b/.github/workflows/remove-awaiting-response-label.yml
@@ -13,7 +13,7 @@ jobs:
       github.event.comment.author_association != 'COLLABORATOR'
     steps:
       - name: Remove needs-reply label
-        uses: octokit/request-action@v2.x
+        uses: octokit/request-action@02f5e7c637a73a3b12ed81015fa7fb5f11cc5d7d # v2.x
         continue-on-error: true
         with:
           route: DELETE /repos/:repository/issues/:issue/labels/:label
diff --git a/.github/workflows/remove-old-issues.yml b/.github/workflows/remove-old-issues.yml
index 51c9b2e41c1..b9589fea9f7 100644
--- a/.github/workflows/remove-old-issues.yml
+++ b/.github/workflows/remove-old-issues.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Close old issues that need reply
-        uses: dwieeb/needs-reply@v2
+        uses: dwieeb/needs-reply@71e8d5144caa0d4a1e292348bfafa3866d08c855 # v2
         with:
           repo-token: ${{ secrets.GITHUB_TOKEN }}
           issue-label: "awaiting response"
diff --git a/.github/workflows/scorecards.yml b/.github/workflows/scorecards.yml
index 818f9d23863..c6e3b51d85e 100644
--- a/.github/workflows/scorecards.yml
+++ b/.github/workflows/scorecards.yml
@@ -32,7 +32,7 @@ jobs:
 
     steps:
       - name: "Checkout code"
-        uses: actions/checkout@v4 # v3.1.0
+        uses: actions/checkout@34e114876b0b11c390a56381ad16ebd13914f8d5 # v4
         with:
           persist-credentials: false
 
diff --git a/tools/docker/demo/Dockerfile b/tools/docker/demo/Dockerfile
index 7783abad272..24e4683c1d2 100644
--- a/tools/docker/demo/Dockerfile
+++ b/tools/docker/demo/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/mirror/docker/library/ubuntu:22.04
+FROM mcr.microsoft.com/mirror/docker/library/ubuntu:22.04@sha256:104ae83764a5119017b8e8d6218fa0832b09df65aae7d5a6de29a85d813da2fb
 
 ARG SYNAPSEML_VERSION=1.1.2
 ARG DEBIAN_FRONTEND=noninteractive
diff --git a/tools/docker/minimal/Dockerfile b/tools/docker/minimal/Dockerfile
index d72981da7b6..566ad04e4d2 100644
--- a/tools/docker/minimal/Dockerfile
+++ b/tools/docker/minimal/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/mirror/docker/library/ubuntu:22.04
+FROM mcr.microsoft.com/mirror/docker/library/ubuntu:22.04@sha256:104ae83764a5119017b8e8d6218fa0832b09df65aae7d5a6de29a85d813da2fb
 
 ARG SYNAPSEML_VERSION=1.1.2
 ARG DEBIAN_FRONTEND=noninteractive
diff --git a/tools/helm/livy/Dockerfile b/tools/helm/livy/Dockerfile
index 19c4fffaac3..9ce97cf6780 100644
--- a/tools/helm/livy/Dockerfile
+++ b/tools/helm/livy/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/openjdk/jdk:11-mariner
+FROM mcr.microsoft.com/openjdk/jdk:11-mariner@sha256:844a36373ab341f993c7258addee6d7d66b6ef93c264ea4b367d96fc5663b7d1
 LABEL maintainer="Dalitso Banda dalitsohb@gmail.com"
 
 # Get Spark from US Apache mirror.
diff --git a/tools/helm/livy/mini.Dockerfile b/tools/helm/livy/mini.Dockerfile
index 07caa82f0e6..fecd622880c 100644
--- a/tools/helm/livy/mini.Dockerfile
+++ b/tools/helm/livy/mini.Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/mmlspark/spark2.4:v4_mini
+FROM mcr.microsoft.com/mmlspark/spark2.4:v4_mini@sha256:a7da0d7cd86ab374d1f0dc7ae4cd35260f8798f8e40a4e4e818748f61a389279
 MAINTAINER Dalitso Banda <dalitsohb@gmail.com>
 
 ENV LIVY_VERSION="git_master"
diff --git a/tools/helm/spark/Dockerfile b/tools/helm/spark/Dockerfile
index d5200fc15a0..2e42b1e7c66 100644
--- a/tools/helm/spark/Dockerfile
+++ b/tools/helm/spark/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/openjdk/jdk:11-mariner
+FROM mcr.microsoft.com/openjdk/jdk:11-mariner@sha256:844a36373ab341f993c7258addee6d7d66b6ef93c264ea4b367d96fc5663b7d1
 LABEL maintainer="Dalitso Banda dalitsohb@gmail.com"
 
 # Get Spark from US Apache mirror.
diff --git a/tools/helm/spark/mini.Dockerfile b/tools/helm/spark/mini.Dockerfile
index 05913f4b0b0..9078ffdb91a 100644
--- a/tools/helm/spark/mini.Dockerfile
+++ b/tools/helm/spark/mini.Dockerfile
@@ -15,7 +15,7 @@
 # limitations under the License.
 #
 
-FROM mcr.microsoft.com/openjdk/jdk:11-mariner
+FROM mcr.microsoft.com/openjdk/jdk:11-mariner@sha256:844a36373ab341f993c7258addee6d7d66b6ef93c264ea4b367d96fc5663b7d1
 
 ARG spark_jars=jars
 ARG img_path=kubernetes/dockerfiles
diff --git a/tools/helm/zeppelin/Dockerfile b/tools/helm/zeppelin/Dockerfile
index 6f92ed02039..b572c2b180a 100644
--- a/tools/helm/zeppelin/Dockerfile
+++ b/tools/helm/zeppelin/Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/openjdk/jdk:11-mariner
+FROM mcr.microsoft.com/openjdk/jdk:11-mariner@sha256:844a36373ab341f993c7258addee6d7d66b6ef93c264ea4b367d96fc5663b7d1
 LABEL maintainer="Dalitso Banda dalitsohb@gmail.com"
 
 # Get Spark from US Apache mirror.
diff --git a/tools/helm/zeppelin/mini.Dockerfile b/tools/helm/zeppelin/mini.Dockerfile
index 6b126a81543..b0f751a4bd5 100644
--- a/tools/helm/zeppelin/mini.Dockerfile
+++ b/tools/helm/zeppelin/mini.Dockerfile
@@ -1,4 +1,4 @@
-FROM mcr.microsoft.com/mmlspark/spark2.4:v4_mini
+FROM mcr.microsoft.com/mmlspark/spark2.4:v4_mini@sha256:a7da0d7cd86ab374d1f0dc7ae4cd35260f8798f8e40a4e4e818748f61a389279
 MAINTAINER Dalitso Banda <dalitsohb@gmail.com>
 
 ADD patch_beam.patch /tmp/patch_beam.patch