Deserialization in Themeum Kirki – Freeform Page Builder, Website Builder & Customizer
CVE-2026-75891
The Kirki plugin for WordPress is vulnerable to Privilege Escalation via PHP Object Injection in all versions up to, and including, 6.2.5 via deserialization of untrusted input through the 'get-single-symbol' branch of the kirki_post_apis() AJAX dispatcher due to a missing capability check. This makes it possible for authenticated attackers, with Subscriber-level access and above, to inject a PHP Object. The additional presence of a POP chain allows attackers to overwrite an administrator's password and gain administrative access.
Vulnerability class: Insecure Deserialization
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
Frequently asked questions
- What is CVE-2026-75891?
- CVE-2026-75891 is a high-severity vulnerability in Themeum Kirki – Freeform Page Builder, Website Builder & Customizer, classified under Deserialization of Untrusted Data. CVSS score: 8.8/10. Published 2026-10-27.
- How severe is CVE-2026-75891?
- High severity. CVSS v3 base score is 8.8 out of 10.