{"vulnerability": "CVE-2026-107843", "sightings": [{"uuid": "795036fc-ed10-4e45-a3ad-684632accaff", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2026-107843", "type": "seen", "source": "https://infosec.exchange/users/cve/statuses/117412610258144245", "content": "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 FORM_SUBMIT or the preceding captcha result. resendActivationMail() can then invoke OptInToken::send() without rate limiting, allowing an unauthenticated attacker to cause repeated activation emails to be sent to an address with a pending registration and to determine whether that pending registration exists. The branch is reachable only when reg_activate is enabled and the target has an unconfirmed registration and opt-in token. This issue is fixed in versions 5.3.50 and 5.7.12.\nhttps://www.cve.org/CVERecord?id=CVE-2026-107843https://github.com/contao/contao/security/advisories/GHSA-mfxh-vp55-7gc6https://github.com/contao/contao/commit/2ea6117f9049db7221679251cfc41e67d941a74bhttps://github.com/contao/contao/releases/tag/5.3.50https://github.com/contao/contao/releases/tag/5.7.12#contao#CVE_2026_107843#bot", "creation_timestamp": "2026-10-09T19:30:53.867228Z"}]}