Contao: The registration module re-sends activation mails
Medium · CVSS 5.3
`ModuleRegistration::compile()` reaches its follow-up registration branch on **any** POST to a page carrying the module. That branch checks neither `FORM_SUBMIT` nor the captcha result computed immediately above it, and `resendActivationMail()` leads to `OptInToken::send()`, which has no rate limit at all. ### Impact Anyone on the internet can make a Contao installation send unlimited mail to an address of their choosing, from the site's own sender and reputation, at one outbound message per HTTP request.
Remediation
Upgrade contao/core-bundle to 5.3.50 or later. Upgrade contao/core-bundle to 5.7.12 or later.
Affected PHP branches
See the source advisory.
Source: GitHub Global Security Advisories (Composer ecosystem) · retrieved 2026-10-22T10:19:14-04:00 · https://github.com/advisories/GHSA-mfxh-vp55-7gc6