diff --git a/wp-includes/embed.php b/wp-includes/embed.php
index c08600de0e..83a824b8ad 100644
--- a/wp-includes/embed.php
+++ b/wp-includes/embed.php
@@ -455,7 +455,7 @@ function get_post_embed_html( $width, $height, $post = null ) {
 		 * and edit wp-embed.js directly.
 		 */
 		$output .= <<<JS
-		!function(a,b){"use strict";function c(){if(!e){e=!0;var a,c,d,f,g=-1!==navigator.appVersion.indexOf("MSIE 10"),h=!!navigator.userAgent.match(/Trident.*rv:11\./),i=b.querySelectorAll("iframe.wp-embedded-content");for(c=0;c<i.length;c++){if(d=i[c],!d.getAttribute("data-secret"))f=Math.random().toString(36).substr(2,10),d.src+="#?secret="+f,d.setAttribute("data-secret",f);if(g||h)a=d.cloneNode(!0),a.removeAttribute("security"),d.parentNode.replaceChild(a,d)}}}var d=!1,e=!1;if(b.querySelector)if(a.addEventListener)d=!0;if(a.wp=a.wp||{},!a.wp.receiveEmbedMessage)if(a.wp.receiveEmbedMessage=function(c){var d=c.data;if(d&&(d.secret||d.message||d.value))if(!/[^a-zA-Z0-9]/.test(d.secret)){var e,f,g,h,i,j=b.querySelectorAll('iframe[data-secret="'+d.secret+'"]'),k=b.querySelectorAll('blockquote[data-secret="'+d.secret+'"]');for(e=0;e<k.length;e++)k[e].style.display="none";for(e=0;e<j.length;e++)if(f=j[e],c.source===f.contentWindow){if(f.removeAttribute("style"),"height"===d.message){if(g=parseInt(d.value,10),g>1e3)g=1e3;else if(~~g<200)g=200;f.height=g}if("link"===d.message)if(h=b.createElement("a"),i=b.createElement("a"),h.href=f.getAttribute("src"),i.href=d.value,i.host===h.host)if(b.activeElement===f)a.top.location.href=d.value}else;}},d)a.addEventListener("message",a.wp.receiveEmbedMessage,!1),b.addEventListener("DOMContentLoaded",c,!1),a.addEventListener("load",c,!1)}(window,document);
+		!function(a,b){"use strict";function c(){if(!e){e=!0;var a,c,d,f,g=-1!==navigator.appVersion.indexOf("MSIE 10"),h=!!navigator.userAgent.match(/Trident.*rv:11\./),i=b.querySelectorAll("iframe.wp-embedded-content");for(c=0;c<i.length;c++){if(d=i[c],!d.getAttribute("data-secret"))f=Math.random().toString(36).substr(2,10),d.src+="#?secret="+f,d.setAttribute("data-secret",f);if(g||h)a=d.cloneNode(!0),a.removeAttribute("security"),d.parentNode.replaceChild(a,d)}}}var d=!1,e=!1;if(b.querySelector)if(a.addEventListener)d=!0;if(a.wp=a.wp||{},!a.wp.receiveEmbedMessage)if(a.wp.receiveEmbedMessage=function(c){var d=c.data;if(d)if(d.secret||d.message||d.value)if(!/[^a-zA-Z0-9]/.test(d.secret)){var e,f,g,h,i,j=b.querySelectorAll('iframe[data-secret="'+d.secret+'"]'),k=b.querySelectorAll('blockquote[data-secret="'+d.secret+'"]');for(e=0;e<k.length;e++)k[e].style.display="none";for(e=0;e<j.length;e++)if(f=j[e],c.source===f.contentWindow){if(f.removeAttribute("style"),"height"===d.message){if(g=parseInt(d.value,10),g>1e3)g=1e3;else if(~~g<200)g=200;f.height=g}if("link"===d.message)if(h=b.createElement("a"),i=b.createElement("a"),h.href=f.getAttribute("src"),i.href=d.value,i.host===h.host)if(b.activeElement===f)a.top.location.href=d.value}else;}},d)a.addEventListener("message",a.wp.receiveEmbedMessage,!1),b.addEventListener("DOMContentLoaded",c,!1),a.addEventListener("load",c,!1)}(window,document);
 JS;
 	}
 	$output .= "\n//--><!]]>";
diff --git a/wp-includes/js/wp-embed.js b/wp-includes/js/wp-embed.js
index fced55559f..887c7483fb 100644
--- a/wp-includes/js/wp-embed.js
+++ b/wp-includes/js/wp-embed.js
@@ -29,7 +29,12 @@
 
 	window.wp.receiveEmbedMessage = function( e ) {
 		var data = e.data;
-		if ( ! data || ! ( data.secret || data.message || data.value ) ) {
+
+		if ( ! data ) {
+			return;
+		}
+
+		if ( ! ( data.secret || data.message || data.value ) ) {
 			return;
 		}
 
diff --git a/wp-includes/js/wp-embed.min.js b/wp-includes/js/wp-embed.min.js
index 36e43a90bc..78f9c6431b 100644
--- a/wp-includes/js/wp-embed.min.js
+++ b/wp-includes/js/wp-embed.min.js
@@ -1 +1 @@
-!function(a,b){"use strict";function c(){if(!e){e=!0;var a,c,d,f,g=-1!==navigator.appVersion.indexOf("MSIE 10"),h=!!navigator.userAgent.match(/Trident.*rv:11\./),i=b.querySelectorAll("iframe.wp-embedded-content");for(c=0;c<i.length;c++){if(d=i[c],!d.getAttribute("data-secret"))f=Math.random().toString(36).substr(2,10),d.src+="#?secret="+f,d.setAttribute("data-secret",f);if(g||h)a=d.cloneNode(!0),a.removeAttribute("security"),d.parentNode.replaceChild(a,d)}}}var d=!1,e=!1;if(b.querySelector)if(a.addEventListener)d=!0;if(a.wp=a.wp||{},!a.wp.receiveEmbedMessage)if(a.wp.receiveEmbedMessage=function(c){var d=c.data;if(d&&(d.secret||d.message||d.value))if(!/[^a-zA-Z0-9]/.test(d.secret)){var e,f,g,h,i,j=b.querySelectorAll('iframe[data-secret="'+d.secret+'"]'),k=b.querySelectorAll('blockquote[data-secret="'+d.secret+'"]');for(e=0;e<k.length;e++)k[e].style.display="none";for(e=0;e<j.length;e++)if(f=j[e],c.source===f.contentWindow){if(f.removeAttribute("style"),"height"===d.message){if(g=parseInt(d.value,10),g>1e3)g=1e3;else if(~~g<200)g=200;f.height=g}if("link"===d.message)if(h=b.createElement("a"),i=b.createElement("a"),h.href=f.getAttribute("src"),i.href=d.value,i.host===h.host)if(b.activeElement===f)a.top.location.href=d.value}else;}},d)a.addEventListener("message",a.wp.receiveEmbedMessage,!1),b.addEventListener("DOMContentLoaded",c,!1),a.addEventListener("load",c,!1)}(window,document);
\ No newline at end of file
+!function(a,b){"use strict";function c(){if(!e){e=!0;var a,c,d,f,g=-1!==navigator.appVersion.indexOf("MSIE 10"),h=!!navigator.userAgent.match(/Trident.*rv:11\./),i=b.querySelectorAll("iframe.wp-embedded-content");for(c=0;c<i.length;c++){if(d=i[c],!d.getAttribute("data-secret"))f=Math.random().toString(36).substr(2,10),d.src+="#?secret="+f,d.setAttribute("data-secret",f);if(g||h)a=d.cloneNode(!0),a.removeAttribute("security"),d.parentNode.replaceChild(a,d)}}}var d=!1,e=!1;if(b.querySelector)if(a.addEventListener)d=!0;if(a.wp=a.wp||{},!a.wp.receiveEmbedMessage)if(a.wp.receiveEmbedMessage=function(c){var d=c.data;if(d)if(d.secret||d.message||d.value)if(!/[^a-zA-Z0-9]/.test(d.secret)){var e,f,g,h,i,j=b.querySelectorAll('iframe[data-secret="'+d.secret+'"]'),k=b.querySelectorAll('blockquote[data-secret="'+d.secret+'"]');for(e=0;e<k.length;e++)k[e].style.display="none";for(e=0;e<j.length;e++)if(f=j[e],c.source===f.contentWindow){if(f.removeAttribute("style"),"height"===d.message){if(g=parseInt(d.value,10),g>1e3)g=1e3;else if(~~g<200)g=200;f.height=g}if("link"===d.message)if(h=b.createElement("a"),i=b.createElement("a"),h.href=f.getAttribute("src"),i.href=d.value,i.host===h.host)if(b.activeElement===f)a.top.location.href=d.value}else;}},d)a.addEventListener("message",a.wp.receiveEmbedMessage,!1),b.addEventListener("DOMContentLoaded",c,!1),a.addEventListener("load",c,!1)}(window,document);
\ No newline at end of file
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 6d0f8a8c79..2b7b3cf9fd 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.0-alpha-43596';
+$wp_version = '5.0-alpha-43597';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.