CVE-2026-70554

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.

CVSS v3 9.8 CRITICAL

9.8^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.9

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/maxsite/cms
https://max-3000.com/page/maxsite-cms-109-6
https://www.vulncheck.com/advisories/maxsite-cms-unauthenticated-php-object-injection-via-maxsite-comuser-cookie

Configurations

No configuration.

History

No history.

Information

Published : 2026-08-04 21:16

Updated : 2026-08-31 20:19

NVD link : CVE-2026-70554

Mitre link : CVE-2026-70554

CVE.ORG link : CVE-2026-70554

JSON object : View

Products Affected

No product.

CWE

CWE-502

Deserialization of Untrusted Data

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