CVE-2026-91939 [CRITICAL] – Cotonti 1.0.0 Comments plugin passes the ci GET parameter to unserialize() without allowed

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.