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CVE-2026-70554

criticalCVSS 9.8covered by 1 sourcefirst seen 2026-08-04
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.

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Advisory coverage (1)

External references

NVD record for CVE-2026-70554

CVE.org record

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