diff --git a/wp-admin/admin-header.php b/wp-admin/admin-header.php
index 8eddb2b892..cd068f1f9b 100644
--- a/wp-admin/admin-header.php
+++ b/wp-admin/admin-header.php
@@ -82,12 +82,12 @@ $admin_body_class = preg_replace( '/[^a-z0-9_-]+/i', '-', $hook_suffix );
 ?>
 <script type="text/javascript">
 addLoadEvent = function(func){if(typeof jQuery!=='undefined')jQuery(document).ready(func);else if(typeof wpOnload!=='function'){wpOnload=func;}else{var oldonload=wpOnload;wpOnload=function(){oldonload();func();}}};
-var ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>',
-	pagenow = '<?php echo $current_screen->id; ?>',
-	typenow = '<?php echo $current_screen->post_type; ?>',
-	adminpage = '<?php echo $admin_body_class; ?>',
-	thousandsSeparator = '<?php echo addslashes( $wp_locale->number_format['thousands_sep'] ); ?>',
-	decimalPoint = '<?php echo addslashes( $wp_locale->number_format['decimal_point'] ); ?>',
+var ajaxurl = '<?php echo esc_js( admin_url( 'admin-ajax.php', 'relative' ) ); ?>',
+	pagenow = '<?php echo esc_js( $current_screen->id ); ?>',
+	typenow = '<?php echo esc_js( $current_screen->post_type ); ?>',
+	adminpage = '<?php echo esc_js( $admin_body_class ); ?>',
+	thousandsSeparator = '<?php echo esc_js( $wp_locale->number_format['thousands_sep'] ); ?>',
+	decimalPoint = '<?php echo esc_js( $wp_locale->number_format['decimal_point'] ); ?>',
 	isRtl = <?php echo (int) is_rtl(); ?>;
 </script>
 <?php
diff --git a/wp-admin/includes/class-custom-image-header.php b/wp-admin/includes/class-custom-image-header.php
index 838ab4a33e..6fb5460df9 100644
--- a/wp-admin/includes/class-custom-image-header.php
+++ b/wp-admin/includes/class-custom-image-header.php
@@ -343,7 +343,7 @@ class Custom_Image_Header {
 		?>
 <script type="text/javascript">
 (function($){
-	var default_color = '<?php echo $default_color; ?>',
+	var default_color = '<?php echo esc_js( $default_color ); ?>',
 		header_text_fields;
 
 	function pickColor(color) {
diff --git a/wp-admin/includes/media.php b/wp-admin/includes/media.php
index 3650e2cb29..11629ae6e9 100644
--- a/wp-admin/includes/media.php
+++ b/wp-admin/includes/media.php
@@ -532,7 +532,7 @@ function wp_iframe( $content_func, ...$args ) {
 	?>
 	<script type="text/javascript">
 	addLoadEvent = function(func){if(typeof jQuery!="undefined")jQuery(document).ready(func);else if(typeof wpOnload!='function'){wpOnload=func;}else{var oldonload=wpOnload;wpOnload=function(){oldonload();func();}}};
-	var ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>', pagenow = 'media-upload-popup', adminpage = 'media-upload-popup',
+	var ajaxurl = '<?php echo esc_js( admin_url( 'admin-ajax.php', 'relative' ) ); ?>', pagenow = 'media-upload-popup', adminpage = 'media-upload-popup',
 	isRtl = <?php echo (int) is_rtl(); ?>;
 	</script>
 	<?php
diff --git a/wp-admin/includes/ms.php b/wp-admin/includes/ms.php
index ff7df62354..282be59071 100644
--- a/wp-admin/includes/ms.php
+++ b/wp-admin/includes/ms.php
@@ -842,7 +842,7 @@ function can_edit_network( $network_id ) {
 function _thickbox_path_admin_subfolder() {
 	?>
 <script type="text/javascript">
-var tb_pathToImage = "<?php echo includes_url( 'js/thickbox/loadingAnimation.gif', 'relative' ); ?>";
+var tb_pathToImage = "<?php echo esc_js( includes_url( 'js/thickbox/loadingAnimation.gif', 'relative' ) ); ?>";
 </script>
 	<?php
 }
diff --git a/wp-admin/includes/template.php b/wp-admin/includes/template.php
index 05be0d92e9..4acbb25afa 100644
--- a/wp-admin/includes/template.php
+++ b/wp-admin/includes/template.php
@@ -2027,12 +2027,12 @@ function iframe_header( $title = '', $deprecated = false ) {
 <script type="text/javascript">
 addLoadEvent = function(func){if(typeof jQuery!="undefined")jQuery(document).ready(func);else if(typeof wpOnload!='function'){wpOnload=func;}else{var oldonload=wpOnload;wpOnload=function(){oldonload();func();}}};
 function tb_close(){var win=window.dialogArguments||opener||parent||top;win.tb_remove();}
-var ajaxurl = '<?php echo admin_url( 'admin-ajax.php', 'relative' ); ?>',
-	pagenow = '<?php echo $current_screen->id; ?>',
-	typenow = '<?php echo $current_screen->post_type; ?>',
-	adminpage = '<?php echo $admin_body_class; ?>',
-	thousandsSeparator = '<?php echo addslashes( $wp_locale->number_format['thousands_sep'] ); ?>',
-	decimalPoint = '<?php echo addslashes( $wp_locale->number_format['decimal_point'] ); ?>',
+var ajaxurl = '<?php echo esc_js( admin_url( 'admin-ajax.php', 'relative' ) ); ?>',
+	pagenow = '<?php echo esc_js( $current_screen->id ); ?>',
+	typenow = '<?php echo esc_js( $current_screen->post_type ); ?>',
+	adminpage = '<?php echo esc_js( $admin_body_class ); ?>',
+	thousandsSeparator = '<?php echo esc_js( $wp_locale->number_format['thousands_sep'] ); ?>',
+	decimalPoint = '<?php echo esc_js( $wp_locale->number_format['decimal_point'] ); ?>',
 	isRtl = <?php echo (int) is_rtl(); ?>;
 </script>
 	<?php
diff --git a/wp-admin/media-new.php b/wp-admin/media-new.php
index cb684c3079..a4df447ceb 100644
--- a/wp-admin/media-new.php
+++ b/wp-admin/media-new.php
@@ -77,9 +77,9 @@ if ( get_user_setting( 'uploader' ) || isset( $_GET['browser-uploader'] ) ) {
 	<?php media_upload_form(); ?>
 
 	<script type="text/javascript">
-	var post_id = <?php echo $post_id; ?>, shortform = 3;
+	var post_id = <?php echo absint( $post_id ); ?>, shortform = 3;
 	</script>
-	<input type="hidden" name="post_id" id="post_id" value="<?php echo $post_id; ?>" />
+	<input type="hidden" name="post_id" id="post_id" value="<?php echo absint( $post_id ); ?>" />
 	<?php wp_nonce_field( 'media-form' ); ?>
 	<div id="media-items" class="hide-if-no-js"></div>
 	</form>
diff --git a/wp-admin/network/site-users.php b/wp-admin/network/site-users.php
index 319051f89d..3de5fd4a51 100644
--- a/wp-admin/network/site-users.php
+++ b/wp-admin/network/site-users.php
@@ -220,7 +220,7 @@ if ( ! wp_is_large_network( 'users' ) && apply_filters( 'show_network_site_users
 require_once ABSPATH . 'wp-admin/admin-header.php'; ?>
 
 <script type="text/javascript">
-var current_site_id = <?php echo $id; ?>;
+var current_site_id = <?php echo absint( $id ); ?>;
 </script>
 
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 28a8ce495e..24de64015e 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.6-beta2-49383';
+$wp_version = '5.6-beta2-49384';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.