diff --git src/js/_enqueues/wp/embed.js src/js/_enqueues/wp/embed.js
index 16e7e8bb41..fced55559f 100644
--- src/js/_enqueues/wp/embed.js
+++ src/js/_enqueues/wp/embed.js
@@ -29,7 +29,7 @@
 
 	window.wp.receiveEmbedMessage = function( e ) {
 		var data = e.data;
-		if ( ! ( data.secret || data.message || data.value ) ) {
+		if ( ! data || ! ( data.secret || data.message || data.value ) ) {
 			return;
 		}