diff --git a/.github/workflows/dependency-review.yml b/.github/workflows/dependency-review.yml
index a1547fb..ab890b6 100644
--- a/.github/workflows/dependency-review.yml
+++ b/.github/workflows/dependency-review.yml
@@ -20,20 +20,17 @@ on:
 # https://docs.github.com/en/enterprise-cloud@latest/code-security/supply-chain-security/understanding-your-software-supply-chain/using-the-dependency-submission-api
 permissions:
   contents: read
-  # Write permissions for pull-requests are required for using the `comment-summary-in-pr` option, comment out if you aren't using this option
-  pull-requests: write
 
 jobs:
   dependency-review:
     runs-on: ubuntu-latest
     steps:
       - name: 'Checkout repository'
-        uses: actions/checkout@v6
+        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
       - name: 'Dependency Review'
-        uses: actions/dependency-review-action@v4
+        uses: actions/dependency-review-action@3c4e3dcb1aa7874d2c16be7d79418e9b7efd6261 # v4
         # Commonly enabled options, see https://github.com/actions/dependency-review-action#configuration-options for all available options.
-        with:
-          comment-summary-in-pr: always
+        # No PR comment output to keep permissions read-only.
         #   fail-on-severity: moderate
         #   deny-licenses: GPL-1.0-or-later, LGPL-2.0-or-later
         #   retry-on-snapshot-warnings: true
diff --git a/.github/workflows/sonarcloud.yml b/.github/workflows/sonarcloud.yml
index 4cdc3b8..114e07b 100644
--- a/.github/workflows/sonarcloud.yml
+++ b/.github/workflows/sonarcloud.yml
@@ -6,19 +6,22 @@ on:
   push:
     branches:
       - main
+permissions: {}
 
 jobs:
   sonarcloud:
     runs-on: ubuntu-latest
+    environment: org-prod
     permissions:
+      id-token: write
       contents: read
       pull-requests: write
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6
         with:
           fetch-depth: 0
 
-      - uses: actions/setup-python@v6
+      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6
         with:
           python-version: '3.12'
 
@@ -28,11 +31,43 @@ jobs:
       - name: Run tests with coverage
         run: make coverage-sonar
 
+      - name: Skip SonarCloud on untrusted fork PR
+        if: ${{ github.event_name == 'pull_request' && (github.event.pull_request.head.repo.fork || !contains(fromJSON('["OWNER","MEMBER","COLLABORATOR"]'), github.event.pull_request.author_association)) }}
+        run: |
+          echo "Skipping SonarCloud token retrieval for untrusted PR context."
+          echo "Fork PRs and non-collaborator authors do not receive Vault-backed token access."
+
+      - name: Azure login (OIDC)
+        if: ${{ github.event_name != 'pull_request' || (github.event.pull_request.head.repo.fork == false && contains(fromJSON('["OWNER","MEMBER","COLLABORATOR"]'), github.event.pull_request.author_association)) }}
+        uses: azure/login@a457da9ea143d694b1b9c7c869ebb04ebe844ef5
+        with:
+          client-id: ${{ vars.AZURE_CLIENT_ID }}
+          tenant-id: ${{ vars.AZURE_TENANT_ID }}
+          subscription-id: ${{ vars.AZURE_SUBSCRIPTION_ID }}
+
+      - name: Read SonarCloud token from Key Vault
+        if: ${{ github.event_name != 'pull_request' || (github.event.pull_request.head.repo.fork == false && contains(fromJSON('["OWNER","MEMBER","COLLABORATOR"]'), github.event.pull_request.author_association)) }}
+        id: sonar_token
+        shell: bash
+        run: |
+          set -euo pipefail
+          SONAR_TOKEN="$(az keyvault secret show \
+            --vault-name "${{ vars.AZURE_KEYVAULT_NAME }}" \
+            --name "sonar-cloud-token" \
+            --query value -o tsv)"
+          if [ -z "${SONAR_TOKEN}" ]; then
+            echo "Key Vault secret sonar-cloud-token is empty."
+            exit 1
+          fi
+          echo "::add-mask::$SONAR_TOKEN"
+          echo "value=$SONAR_TOKEN" >> "$GITHUB_OUTPUT"
+
       - name: SonarCloud scan
-        uses: SonarSource/sonarcloud-github-action@ffc3010689be73b8e5ae0c57ce35968afd7909e8
+        if: ${{ github.event_name != 'pull_request' || (github.event.pull_request.head.repo.fork == false && contains(fromJSON('["OWNER","MEMBER","COLLABORATOR"]'), github.event.pull_request.author_association)) }}
+        uses: SonarSource/sonarqube-scan-action@a31c9398be7ace6bbfaf30c0bd5d415f843d45e9 # v7.0.0
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
+          SONAR_TOKEN: ${{ steps.sonar_token.outputs.value }}
         with:
           args: >
             -Dsonar.host.url=https://sonarcloud.io
@@ -43,10 +78,11 @@ jobs:
             -Dsonar.enableIssueAnnotation=true
 
       - name: SonarCloud quality gate
+        if: ${{ github.event_name != 'pull_request' || (github.event.pull_request.head.repo.fork == false && contains(fromJSON('["OWNER","MEMBER","COLLABORATOR"]'), github.event.pull_request.author_association)) }}
         uses: SonarSource/sonarqube-quality-gate-action@cf038b0e0cdecfa9e56c198bbb7d21d751d62c3b
         with:
           scanMetadataReportFile: dist/quality/sonar/scannerwork/report-task.txt
         env:
-          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
+          SONAR_TOKEN: ${{ steps.sonar_token.outputs.value }}
           SONAR_HOST_URL: https://sonarcloud.io
         timeout-minutes: 5