CVE-2026-70554 — MaxSite CMS Unauthenticated PHP Object Injection via maxsite_comuser Cookie
MaxSite CMS contains a PHP object injection vulnerability that allows unauthenticated attackers to execute arbitrary code by passing attacker-controlled serialized data in the m…
Published: 2026-08-04 · CVSS: 9.3 · CVSS 4.0
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.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7