VULNERABILITY INTELLIGENCE
CVE-2026-70554
CVSS score9.3 CRITICAL
EPSS probability1.23%
CISA KEVNot currently listed
Published2026-08-04
Last modified2026-10-24
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Description
MaxSite CMS contains a PHP object injection vulnerability that allows unauthenticated attackers to execute arbitrary code by passing attacker-controlled serialized data in the maxsite_comuser cookie directly to unserialize() without validation or class allowlisting. Attackers can craft a malicious serialized PHP object payload delivered in a single HTTP request to trigger magic methods during object graph reconstruction, enabling property-oriented programming attacks or remote code execution via available gadget chains such as those targeting SoapClient or Imagick extensions.
Weakness classification
- CWE-502: Deserialization of Untrusted Data