diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index e6ea871caf7d..fe6822ef51cc 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -53,8 +53,10 @@ env:
   DISABLE_V8_COMPILE_CACHE: '1'
 
 # Jobs that install the monorepo dependencies share one Namespace cache volume through `overrides.cache-tag`, E2E jobs
-# share another one (`-e2e`). Jobs that do not use a cache volume have no cache tag. Pull request jobs get their own
-# volumes (`-pr`), so they cannot change the node_modules that develop and release builds install from.
+# share another one (`-e2e`). The optional Cloudflare integration tests replace the installed wrangler with the latest
+# one, so they use a third one (`-latest-wrangler`). Jobs that do not use a cache volume have no cache tag. Pull request
+# jobs get their own volumes (`-pr`), so they cannot change the node_modules that develop and release builds install
+# from.
 jobs:
   job_get_metadata:
     uses: ./.github/workflows/ci-metadata.yml
@@ -857,6 +859,7 @@ jobs:
         working-directory: dev-packages/node-integration-tests
         run: pnpm run test --shard=${{ matrix.shard }}/3
 
+  # Runs on the wrangler pinned in the package, so the required run stays on a fixed, older runtime.
   job_cloudflare_integration_tests:
     name: Cloudflare Integration Tests (${{ matrix.shard }}/2)
     needs: [job_get_metadata, job_build]
@@ -869,7 +872,7 @@ jobs:
       fail-fast: false
       matrix:
         shard: [1, 2]
-    steps:
+    steps: &cloudflare_integration_tests_steps
       - name: Check out current commit (${{ needs.job_get_metadata.outputs.commit_label }})
         uses: actions/checkout@v7
         with:
@@ -881,10 +884,40 @@ jobs:
       - name: Restore caches
         uses: ./.github/actions/restore-cache
 
+      # The Vite plugin depends on wrangler and writes config for it, so both move together. In the hoisted layout,
+      # pnpm keeps the nested `node_modules` folders of the old versions (for example an old workerd under
+      # `node_modules/wrangler`), so the install starts from empty `node_modules` folders. They are mount points of the
+      # cache volume, so only their contents are deleted.
+      - name: Install the latest wrangler
+        if: matrix.wrangler == 'latest'
+        run: |
+          pnpm --filter @sentry-internal/cloudflare-integration-tests add --save-dev --lockfile-only wrangler@latest @cloudflare/vite-plugin@latest
+          find -H node_modules packages/*/node_modules dev-packages/*/node_modules -mindepth 1 -maxdepth 1 -exec rm -rf {} +
+          pnpm install --frozen-lockfile --filter @sentry-internal/cloudflare-integration-tests...
+
       - name: Run integration tests
         working-directory: dev-packages/cloudflare-integration-tests
         run: pnpm run test --shard=${{ matrix.shard }}/2
 
+  # Shows breakage from new wrangler and workerd releases early. It is not in `job_required_jobs_passed`, so it cannot
+  # block a PR, and like the optional E2E tests it does not run on release branches.
+  job_optional_cloudflare_integration_tests:
+    name: Cloudflare Integration Tests (${{ matrix.shard }}/2, latest wrangler) (optional)
+    needs: [job_get_metadata, job_build]
+    if:
+      needs.job_get_metadata.outputs.is_release != 'true' && (needs.job_build.outputs.changed_cloudflare_integration ==
+      'true' || github.event_name != 'pull_request')
+    runs-on:
+      namespace-profile-sentry-javascript;overrides.cache-tag=sentry-javascript-latest-wrangler${{ github.event_name ==
+      'pull_request' && '-pr' || '' }}
+    timeout-minutes: 15
+    strategy:
+      fail-fast: false
+      matrix:
+        shard: [1, 2]
+        wrangler: [latest]
+    steps: *cloudflare_integration_tests_steps
+
   job_bundler_plugin_integration_tests:
     name: Bundler Plugin Integration Tests (Node ${{ matrix.node }})
     needs: [job_get_metadata, job_build]
diff --git a/dev-packages/cloudflare-integration-tests/runner.ts b/dev-packages/cloudflare-integration-tests/runner.ts
index 69ab9e20fc2e..984c79480d68 100644
--- a/dev-packages/cloudflare-integration-tests/runner.ts
+++ b/dev-packages/cloudflare-integration-tests/runner.ts
@@ -489,6 +489,8 @@ export function createRunner(...paths: string[]) {
                 'false',
                 '--var',
                 `SENTRY_DSN:http://public@localhost:${mockServerPort}/1337`,
+                '--ip',
+                '127.0.0.1',
                 '--port',
                 '0',
                 '--inspector-port',
@@ -521,6 +523,10 @@ export function createRunner(...paths: string[]) {
               `SENTRY_DSN:http://public@localhost:${mockServerPort}/1337`,
               '--var',
               `SERVER_URL:${serverUrl}`,
+              // Requests go to `localhost`, which can resolve to `::1`. The IPv4 listener keeps the
+              // client address at `127.0.0.1`, which the event expectations check.
+              '--ip',
+              '127.0.0.1',
               '--port',
               '0',
               '--inspector-port',