CVE-2026-100523: Cotonti

Medium severity, CVSS 6.1. EPSS: 0.2% chance of exploitation in the next 30 days.

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.

Affected products

• Cotonti Cotonti: up to and including 1.0.0

Published 2026-09-26. Last modified 2026-10-05.