CVE-2026-70554

Summary

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.

Affected Software

VendorProductVersion RangeStatus
MaxSiteMaxSite CMS0.78 <= 109.5affected
MaxSiteMaxSite CMS109.6unaffected

Weaknesses

  • CWE-502: Deserialization of Untrusted Data

References