{"id":"CVE-2026-107843","published":"2026-10-09T20:17:10.167","lastModified":"2026-10-13T18:17:16.130","description":"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.","cvssScore":5.3,"cvssSeverity":"MEDIUM","cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","cwes":["CWE-204","CWE-770"],"vendors":[],"products":[],"references":[{"url":"https://github.com/contao/contao/commit/2ea6117f9049db7221679251cfc41e67d941a74b","tags":[]},{"url":"https://github.com/contao/contao/releases/tag/5.3.50","tags":[]},{"url":"https://github.com/contao/contao/releases/tag/5.7.12","tags":[]},{"url":"https://github.com/contao/contao/security/advisories/GHSA-mfxh-vp55-7gc6","tags":[]}],"exploitRefs":[{"url":"https://github.com/contao/contao/commit/2ea6117f9049db7221679251cfc41e67d941a74b","tags":[]},{"url":"https://github.com/contao/contao/releases/tag/5.3.50","tags":[]},{"url":"https://github.com/contao/contao/releases/tag/5.7.12","tags":[]},{"url":"https://github.com/contao/contao/security/advisories/GHSA-mfxh-vp55-7gc6","tags":[]}],"hasPoc":true,"ai":null}