Contao: The registration module re-sends activation mails on any unauthenticated POST, with no throttle and no captcha check

{
                    "vendor": "contao",
                    "product": "contao",
                    "versions": [
                        {
                            "version": ">= 4.1.0, < 5.3.50",
                            "status": "affected"
                        },
                        {
                            "version": ">= 5.4.0-RC1, < 5.7.12",
                            "status": "affected"
                        }
                    ]
                }