CVE-2026-25818

Critical severity, CVSS 9.1. EPSS: 0.2% chance of exploitation in the next 30 days.

HMS Networks Ewon Flexy with firmware before 15.0s4, Cosy+ with firmware 22.xx before 22.1s6, and Cosy+ with firmware 23.xx before 23.0s3 have weak entropy for authentication cookies, allowing an attacker with a stolen session cookie to find the user password by brute-forcing an encryption parameter.

Published 2026-03-13. Last modified 2026-06-17.