YUNUCMS 1.1.8 has XSS in app/admin/controller/System.php because crafted data can be written to the sys.php file, as demonstrated by site_title in an admin/system/basic POST request.
statics/app/index/controller/Install.php in YUNUCMS 1.1.5 (if install.lock is not present) allows remote attackers to execute arbitrary PHP code by placing this code in the index.php?s=index/install/setup2 DB_PREFIX field, which is written to database.php.
statics/ueditor/php/vendor/Local.class.php in YUNUCMS 1.1.5 allows arbitrary file deletion via the statics/ueditor/php/controller.php?action=remove key parameter, as demonstrated by using directory traversal to delete the install.lock file.