Ticket #40935: 40935.1.diff

src/wp-admin/js/widgets/media-widgets.js

@@ -184 +184 @@
                                                         return;
                                                 }
 
+                                                // If video, test for Vimeo and YouTube, otherwise, renderFail().
+                                                if ( 'video' === this.controller.options.mimeType && ! /vimeo|youtu\.?be/.test( urlParser.host ) ) {
+                                                        embedLinkView.renderFail();
+                                                        return;
+                                                }
+
                                                 embedLinkView.dfd = $.ajax({
                                                         url: wp.media.view.settings.oEmbedProxyUrl,
                                                         data: {