{"cve":"CVE-2026-100523","nvd":{"published":"2026-09-26T01:17:00.870","modified":"2026-10-05T15:17:10.117","status":"Deferred","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.","cvss_v4":{"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","score":5.1},"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","score":6.1},"cwes":["CWE-601"],"references":["https://github.com/Cotonti/Cotonti","https://github.com/Cotonti/Cotonti/blob/1.0.0/message.php","https://github.com/Cotonti/Cotonti/blob/1.0.0/system/common.php","https://github.com/Cotonti/Cotonti/issues/1907","https://github.com/Cotonti/Cotonti/pull/1908"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:56:48.555445741+00:00"},"epss":{"cve":"CVE-2026-100523","score":0.00188,"percentile":0.08284,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}