Deserialization in Themeum Kirki – Freeform Page Builder, Website Builder & Customizer

CVE-2026-104734

The Kirki – Freeform Page Builder, Website Builder & Customizer plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 6.3.2 via deserialization of untrusted input . This makes it possible for authenticated attackers, with administrator-level access and above, to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present. By default, Editor-level users are granted FULL_ACCESS to the plugin's import endpoint via the KIRKI_USERS_DEFAULT_FULL_ACCESS configuration, meaning exploitation is possible at Editor privilege level rather than being restricted to administrators alone.

Vulnerability class: Insecure Deserialization

Published 2026-10-17.