@@ -1,35 +1,52 @@
 name: First commit message adheres to guidelines
 
 on:
-  pull_request:
+  pull_request_target:
     branches:
       - main
 
 env:
   NODE_VERSION: lts/*
 
 permissions:
-  contents: read
+  pull-requests: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
 
 jobs:
   lint-commit-message:
+    name: lint-commit-message
     runs-on: ubuntu-slim
     steps:
-      - name: Compute number of commits in the PR
-        id: nb-of-commits
-        run: |
-          echo "plusOne=$((${{ github.event.pull_request.commits }} + 1))" >> $GITHUB_OUTPUT
-          echo "minusOne=$((${{ github.event.pull_request.commits }} - 1))" >> $GITHUB_OUTPUT
-      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
-        with:
-          fetch-depth: ${{ steps.nb-of-commits.outputs.plusOne }}
-          persist-credentials: false
-      - run: git reset HEAD^2
       - name: Install Node.js
         uses: actions/setup-node@820762786026740c76f36085b0efc47a31fe5020  # v7.0.0
         with:
           node-version: ${{ env.NODE_VERSION }}
-      - name: Validate commit message
-        run: |
-          echo "::add-matcher::.github/workflows/commit-lint-problem-matcher.json"
-          git rev-parse HEAD~${{ steps.nb-of-commits.outputs.minusOne }} | xargs npx -q core-validate-commit --no-validate-metadata --tap
+      - name: Validate first commit message
+        uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3  # v9.0.0
+        with:
+          script: |
+            const { data: [commit] } = await github.rest.pulls.listCommits({
+              ...context.repo,
+              pull_number: context.issue.number,
+              per_page: 1,
+            });
+            if (!commit) {
+              throw new Error('No commits found in pull request');
+            }
+            const { exitCode, stdout, stderr } = await exec.getExecOutput('npx', [
+              '-q', '--yes', '--ignore-scripts', 'core-validate-commit@6.0.0',
+              '--no-validate-metadata', '--tap', '-',
+            ], {
+              cwd: process.env.RUNNER_TEMP,
+              input: Buffer.from(JSON.stringify([{ id: commit.sha, message: commit.commit.message }])),
+              silent: true,
+              ignoreReturnCode: true,
+            });
+            if (exitCode !== 0) {
+              core.setFailed(stdout + stderr || 'Commit message validation failed');
+            } else {
+              core.info('First commit message passes validation');
+            }