CVE-2026-91939

Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed_classes restriction, allowing unauthenticated attackers to instantiate arbitrary PHP classes with attacker-controlled properties. Attackers can exploit PHP object injection through crafted serialized payloads to trigger gadget chains and achieve database manipulation or code execution.

  • Published Sep 15, 2026
  • CVSS 9.3 critical
  • 1.0% chance of exploitation in the next 30 days (EPSS)

Affected software

CVE-2026-91939 at the National Vulnerability Database