diff --git src/wp-includes/default-widgets.php src/wp-includes/default-widgets.php
index 7ad17f3..17d2232 100644
--- src/wp-includes/default-widgets.php
+++ src/wp-includes/default-widgets.php
@@ -1323,7 +1323,19 @@ class WP_Widget_Tag_Cloud extends WP_Widget {
 		if ( !empty($instance['title']) )
 			echo $args['before_title'] . $instance['title'] . $args['after_title'];
 
-		wp_nav_menu( array( 'fallback_cb' => '', 'menu' => $nav_menu ) );
+		/**
+		 * Filter the arguments for the Custom Menu widget.
+		 *
+		 * @since 4.1.0
+		 *
+		 * @see wp_nav_menu()
+		 *
+		 * @param array $args An array of arguments to retrieve the custom menu.
+		 */
+		wp_nav_menu( apply_filters( 'widget_nav_menu_args', array(
+			'fallback_cb' => '',
+			'menu'        => $nav_menu
+		) ) );
 
 		echo $args['after_widget'];
 	}