CVE-2026-91939

Description

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.

References

• https://github.com/Cotonti/Cotonti
• https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/comments.setup.php
• https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/controllers/actions/DisplayAction.php
• https://github.com/Cotonti/Cotonti/blob/1.0.0/plugins/comments/inc/CommentsWidget.php
• https://github.com/Cotonti/Cotonti/issues/1888