CVE-2026-87930: Maxsite CMS

High severity, CVSS 8.1. EPSS: 0.6% chance of exploitation in the next 30 days.

MaxSite CMS through 109.6 passes the ci_session cookie to unserialize() without class restrictions, allowing unauthenticated attackers to inject PHP objects. Attackers can forge valid session cookies using the hardcoded encryption key to trigger magic methods and corrupt application state or achieve code execution if gadget classes exist.

Affected products

• Maxsite Maxsite CMS: from 0.78, up to and including 109.6

Published 2026-09-09. Last modified 2026-09-09.