diff --git a/content/public/android/java/src/org/chromium/content/browser/input/SelectPopup.java b/content/public/android/java/src/org/chromium/content/browser/input/SelectPopup.java
--- a/content/public/android/java/src/org/chromium/content/browser/input/SelectPopup.java
+++ b/content/public/android/java/src/org/chromium/content/browser/input/SelectPopup.java
@@ -97,8 +97,13 @@ public class SelectPopup
     }

     /** Close popup. Called when {@link WindowAndroid} is updated. */
     public void close() {
+        // Dismiss the live AlertDialog/DropdownPopupWindow before dropping the
+        // reference, otherwise the orphaned dialog's listeners can later call
+        // selectMenuItems() against a re-bound popup_client_ (cross-popup
+        // misdelivery) or an unbound one (browser-process near-null crash).
+        if (mPopupView != null) mPopupView.hide(/*sendsCancelMessage=*/true);
         mPopupView = null;
     }

diff --git a/content/browser/android/select_popup.cc b/content/browser/android/select_popup.cc
--- a/content/browser/android/select_popup.cc
+++ b/content/browser/android/select_popup.cc
@@ -139,9 +139,14 @@ void SelectPopup::SelectMenuItems(JNIEnv* env,
                                   int64_t selectPopupDelegate,
                                   const JavaRef<jintArray>& indices) {
   blink::mojom::PopupMenuClient* popup_client_raw_ptr =
       reinterpret_cast<blink::mojom::PopupMenuClient*>(selectPopupDelegate);
-  DCHECK(popup_client_raw_ptr && popup_client_.get() == popup_client_raw_ptr);
+  // Defense-in-depth: refuse to dispatch if the Java-side delegate no longer
+  // matches the currently-bound client (orphaned dialog from a prior
+  // WindowAndroid swap) or if the remote was reset.
+  if (!popup_client_ || popup_client_.get() != popup_client_raw_ptr) {
+    return;
+  }

   if (indices.is_null()) {
     popup_client_->DidCancel();
     return;