Ticket #41901: patch-41901.diff

wp-admin/includes/ajax-actions.php

@@ -3477 +3477 @@
                 ) );
         }
 
-        $stylesheet = preg_replace( '/[^A-z0-9_\-]/', '', wp_unslash( $_POST['slug'] ) );
+        $stylesheet = preg_replace( '/[^A-z0-9_\-]/', '', $_POST['slug'] );
         $status     = array(
                 'update'     => 'theme',
                 'slug'       => $stylesheet,