CVE-2026-100523

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 Sep 26, 2026
  • CVSS 5.1 medium
  • 0.2% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-100523 at the National Vulnerability Database