{"id":"CVE-2026-100523","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-100523","generatedAt":"2026-10-28T00:54:01.002Z","title":"Cotonti through 1.0.0 contains an open redirect vulnerability in message.php that base64-decodes the redirect parameter without domain validation.","description":"Cotonti through 1.0.0 contains an open redirect vulnerability in message.php that base64-decodes the redirect parameter without domain validation. Unauthenticated attackers can craft malicious links with encoded external URLs to redirect users to arbitrary sites via meta refresh tags for phishing attacks.","published":"2026-09-26T01:17:01.000Z","lastModified":"2026-10-05T15:17:10.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":5.1,"severity":"MEDIUM","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-601"],"affected":[],"epss":{"score":0.00188,"percentile":0.08278,"date":"2026-10-26","history":[{"date":"2026-09-26","score":0.00188,"percentile":0.07501}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.19%). Track it; it rarely justifies an emergency change on its own."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-26T01:17:01.000Z","detail":{"score":"5.1","severity":"MEDIUM","publishedAt":"2026-09-26T01:17:00.870Z"},"summary":"New CVE, medium severity (CVSS 5.1)."}],"references":[{"url":"https://github.com/Cotonti/Cotonti","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/blob/1.0.0/message.php","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/blob/1.0.0/system/common.php","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/issues/1907","source":"disclosure@vulncheck.com"},{"url":"https://github.com/Cotonti/Cotonti/pull/1908","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/cotonti-through-1.0.0-open-redirect-via-message-php-redirect-parameter","source":"disclosure@vulncheck.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-100523","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}