Information disclosed from error page can be used to gain additional information about the target system.
One of the main features of debug mode is the display of detailed error pages. If your app raises an exception when APP_DEBUG is True, Laravel will display a detailed traceback, including a lot of metadata about your environment, such as all the currently defined Laravel settings. If an attacker can find debug error page, this is likely to disclose sensitive information about the web application and supporting infrastructure that may be valuable in formulating targeted attacks against the system.
Never deploy a site into production with DEBUG turned on. To disable debug mode, set APP_DEBUG = False in your Laravel settings file.