diff --git a/.github/workflows/backport.yml b/.github/workflows/backport.yml
index 8ec4f042ed..b177a33a00 100644
--- a/.github/workflows/backport.yml
+++ b/.github/workflows/backport.yml
@@ -2,6 +2,9 @@ on:
   pull_request_target:
     types: ["labeled", "closed"]
 
+permissions:
+  contents: read
+
 jobs:
   backport:
     name: Backport PR
@@ -18,7 +21,7 @@ jobs:
       contents: write
     steps:
       - name: Backport Action
-        uses: sqren/backport-github-action@v8.9.7
+        uses: sqren/backport-github-action@e325a2d70df7264afa24c92b1d5feb2278ff63af # v8.9.7
         with:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           auto_backport_label_prefix: backport-to-
diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 9af1c1ddca..31f4300814 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -45,7 +45,7 @@ jobs:
            done
 
       - name: Publish Test Results
-        uses: EnricoMi/publish-unit-test-result-action@v2
+        uses: EnricoMi/publish-unit-test-result-action@4e7013f9576bd22ffdae979dc6e68cb9ec2aeece # v2.7.0
         with:
           commit: ${{ github.event.workflow_run.head_sha }}
           event_file: artifacts/Event File/event.json
diff --git a/.github/workflows/maven.yml b/.github/workflows/maven.yml
index b54da2b191..617f734992 100644
--- a/.github/workflows/maven.yml
+++ b/.github/workflows/maven.yml
@@ -23,9 +23,9 @@ jobs:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-latest]
     steps:
-    - uses: actions/checkout@v3
+    - uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
     - name: Set up Java
-      uses: actions/setup-java@v3
+      uses: actions/setup-java@5ffc13f4174014e2d4d4572b3d74c3fa61aeb2c2 # v3.11.0
       with:
         java-version: |
             8
@@ -34,14 +34,14 @@ jobs:
             17
         distribution: 'temurin'
     - name: Cache local Maven repository
-      uses: actions/cache@v3
+      uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8 # v3.3.1
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-tycho4m39-${{ matrix.os }}-${{ hashFiles('**/pom.xml', '**/*.target') }}
         restore-keys: |
           ${{ runner.os }}-tycho4m39-${{ matrix.os }}-
     - name: Set up Maven
-      uses: stCarolas/setup-maven@v4.5
+      uses: stCarolas/setup-maven@07fbbe97d97ef44336b7382563d66743297e442f # v4.5
       with:
         maven-version: 3.9.2
     - name: Build Tycho
@@ -51,7 +51,7 @@ jobs:
         cp .github/toolchains.xml ~/.m2/toolchains.xml
         mvn -U -V -e -B -ntp clean install --file pom.xml -DtrimStackTrace=false -Pits -fae
     - name: Upload Test Results
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
       if: always()
       with:
         name: test-results-${{ matrix.os }}
@@ -63,7 +63,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Upload
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
       with:
         name: Event File
         path: ${{ github.event_path }}
diff --git a/.github/workflows/sitedocs.yml b/.github/workflows/sitedocs.yml
index 0a6e9c563a..17c3dfcbe8 100644
--- a/.github/workflows/sitedocs.yml
+++ b/.github/workflows/sitedocs.yml
@@ -7,6 +7,9 @@ on:
     branches: 
       - 'master'
       - 'tycho-*'
+permissions:
+  contents: read
+
 jobs:
   build:
     name: Publish site-docs
@@ -18,31 +21,31 @@ jobs:
       repository-projects: write
     steps:
     - name: Inject slug/short variables
-      uses: rlespinasse/github-slug-action@v4.4.1
+      uses: rlespinasse/github-slug-action@102b1a064a9b145e56556e22b18b19c624538d94 # v4.4.1
     - name: Checkout tycho code
-      uses: actions/checkout@v3
+      uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
       with:
        path: 'tycho'
     - name: Checkout page
-      uses: actions/checkout@v3
+      uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
       with:
        path: 'page'
        token: ${{ secrets.TYCHO_SITE_PAT }}
        repository: 'eclipse-tycho/eclipse-tycho.github.io'
     - name: Set up Java
-      uses: actions/setup-java@v3
+      uses: actions/setup-java@5ffc13f4174014e2d4d4572b3d74c3fa61aeb2c2 # v3.11.0
       with:
         java-version: 17
         distribution: 'temurin'
     - name: Cache local Maven repository
-      uses: actions/cache@v3
+      uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8 # v3.3.1
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-maven-site-${{ hashFiles('**/pom.xml', '**/*.target') }}
         restore-keys: |
           ${{ runner.os }}-maven-site-
     - name: Set up Maven
-      uses: stCarolas/setup-maven@v4.5
+      uses: stCarolas/setup-maven@07fbbe97d97ef44336b7382563d66743297e442f # v4.5
       with:
         maven-version: 3.9.2
     - name: Build site-doc
@@ -51,7 +54,7 @@ jobs:
       run: | 
         mvn -U -V -e -B -ntp clean install site site:stage --file tycho/pom.xml -T1C -DskipTests
     - name: Upload site-doc
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@0b7f8abb1508181956e8e162db84b466c27e18ce # v3.1.2
       with:
         name: site-docs-${{ env.GITHUB_REF_NAME }}
         if-no-files-found: error
diff --git a/.github/workflows/verify-platform.yml b/.github/workflows/verify-platform.yml
index 7b4f968b84..b66386f4cf 100644
--- a/.github/workflows/verify-platform.yml
+++ b/.github/workflows/verify-platform.yml
@@ -15,11 +15,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout tycho code
-      uses: actions/checkout@v3
+      uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
       with:
        path: 'tycho'
     - name: Checkout platform code
-      uses: actions/checkout@v3
+      uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
       with:
        path: 'platform'
        submodules: 'recursive'
@@ -27,7 +27,7 @@ jobs:
        repository: 'eclipse-platform/eclipse.platform.releng.aggregator'
        fetch-depth: 0
     - name: Set up Java
-      uses: actions/setup-java@v3
+      uses: actions/setup-java@5ffc13f4174014e2d4d4572b3d74c3fa61aeb2c2 # v3.11.0
       with:
         java-version: |
             8
@@ -36,14 +36,14 @@ jobs:
             17
         distribution: 'temurin'
     - name: Cache local Maven repository
-      uses: actions/cache@v3
+      uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8 # v3.3.1
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-maven-verify-platform-${{ hashFiles('**/pom.xml', '**/*.target') }}
         restore-keys: |
           ${{ runner.os }}-maven-verify-platform-
     - name: Set up Maven
-      uses: stCarolas/setup-maven@v4.5
+      uses: stCarolas/setup-maven@07fbbe97d97ef44336b7382563d66743297e442f # v4.5
       with:
         maven-version: 3.9.2
     - name: Build Tycho
diff --git a/.github/workflows/verify-platform2.yml b/.github/workflows/verify-platform2.yml
index bb2443115e..637b8cc375 100644
--- a/.github/workflows/verify-platform2.yml
+++ b/.github/workflows/verify-platform2.yml
@@ -15,11 +15,11 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - name: Checkout tycho code
-      uses: actions/checkout@v3
+      uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
       with:
        path: 'tycho'
     - name: Checkout platform code
-      uses: actions/checkout@v3
+      uses: actions/checkout@8e5e7e5ab8b370d6c329ec480221332ada57f0ab # v3.5.2
       with:
        path: 'platform'
        submodules: 'recursive'
@@ -27,7 +27,7 @@ jobs:
        repository: 'eclipse-platform/eclipse.platform'
        fetch-depth: 0
     - name: Set up Java
-      uses: actions/setup-java@v3
+      uses: actions/setup-java@5ffc13f4174014e2d4d4572b3d74c3fa61aeb2c2 # v3.11.0
       with:
         java-version: |
             8
@@ -36,14 +36,14 @@ jobs:
             17
         distribution: 'temurin'
     - name: Cache local Maven repository
-      uses: actions/cache@v3
+      uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8 # v3.3.1
       with:
         path: ~/.m2/repository
         key: ${{ runner.os }}-maven-verify-platform-individual-${{ hashFiles('**/pom.xml', '**/*.target') }}
         restore-keys: |
           ${{ runner.os }}-maven-verify-platform-individual-
     - name: Set up Maven
-      uses: stCarolas/setup-maven@v4.5
+      uses: stCarolas/setup-maven@07fbbe97d97ef44336b7382563d66743297e442f # v4.5
       with:
         maven-version: 3.9.2
     - name: Build Tycho
@@ -58,7 +58,7 @@ jobs:
         --global-toolchains ${{ github.workspace }}/tycho/.github/toolchains.xml
         clean install
     - name: Run Platform Build
-      uses: GabrielBB/xvfb-action@v1
+      uses: GabrielBB/xvfb-action@86d97bde4a65fe9b290c0b3fb92c2c4ed0e5302d # v1.6
       env:
        JAVA_HOME: ${{ env.JAVA_HOME_17_X64 }}
       with: