Contao: The registration module re-sends activation mails — GHSA-MFXH-VP55-7GC6

Summary

`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…

Timeline

Published by source

2026-10-09

Risk context

• Reported severity or threat level: medium.
• Reported CVSS score: 5.3 out of 10.
• Review exposure for the affected product or family: composer: contao/core-bundle.

Product

composer: contao/core-bundle

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-MFXH-VP55-7GC6

Source

GitHub

Vendor

GitHub

Published by source

2026-10-09

Last source activity

2026-10-09

Additional identifiers

CVE-2026-107843

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.