diff --git a/ui/views/controls/menu/menu_controller.cc b/ui/views/controls/menu/menu_controller.cc
index c58f75ab1bfba..29413c2e8598d 100644
--- a/ui/views/controls/menu/menu_controller.cc
+++ b/ui/views/controls/menu/menu_controller.cc
@@ -2527,7 +2527,16 @@ void MenuController::OpenMenuImpl(MenuItemView* item, bool show) {
     } else {
       params.context = owner_;
     }
+    base::WeakPtr<MenuController> weak_this = AsWeakPtr();
     item->GetSubmenu()->ShowAt(params);
+    // ShowAt() can synchronously re-enter and destroy `this` and the
+    // MenuItemView tree (e.g. focus changes during ShowInactive() on macOS
+    // reach MenuRunnerImpl::OnMenuClosed()). The inner frames at
+    // SubmenuView::ShowAt() and MenuHost::ShowMenuHost() guard themselves,
+    // but this frame and its callers (OpenMenu / CommitPendingSelection /
+    // SetSelection / Run) do not. Crash safely instead of dereferencing
+    // freed `item` below and writing to freed `this->showing_submenu_`.
+    CHECK(weak_this);
 
     // Figure out if the mouse is under the menu; if so, remember the mouse
     // location so we can ignore the first mouse move event(s) with that