{"id":"CVE-2026-107843","revision":"32667225dac24496974c45e221e37b3d","records":[{"revision":"32667225dac24496974c45e221e37b3d","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-107843","aliases":[],"title":"Contao: The registration module re-sends activation mails on any unauthenticated POST, with no throttle and no captcha check","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.","state":0,"publishedAt":"2026-10-09T19:21:32.011+00:00","modifiedAt":"2026-10-13T17:08:23.664+00:00","affected":[{"ecosystem":"Vendor product","name":"contao","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"vendor\": \"contao\",\n                    \"product\": \"contao\",\n                    \"versions\": [\n                        {\n                            \"version\": \">= 4.1.0, < 5.3.50\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \">= 5.4.0-RC1, < 5.7.12\",\n                            \"status\": \"affected\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","score":5.3,"severity":"MEDIUM"}],"references":["https://github.com/contao/contao/security/advisories/GHSA-mfxh-vp55-7gc6","https://github.com/contao/contao/commit/2ea6117f9049db7221679251cfc41e67d941a74b","https://github.com/contao/contao/releases/tag/5.3.50","https://github.com/contao/contao/releases/tag/5.7.12"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-107843","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-107843","identifiers":["CVE-2026-107843"]},"retained":false,"historicalAffected":[]}],"coverage":[]}