CVE-2026-107843 Contao: The registration module re-sends activation mails on any unauthenticated POST, with no throttle and no captcha check

Contao is an Open Source CMS. From version 4.1.0 until 5.3.50 and 5.7.12, ModuleRegistration::compile enters its follow-up registration branch on any POST to a page containing the registration module without verifying FORMSUBMIT or the preceding captcha result. resendActivationMail can then invok...