Kirki <= 6.2.5 - Authenticated (Subscriber+) PHP Object Injection to Administrator Account Takeover via 'get-single-symbol' AJAX Endpoint
Strategic Overview
- Status
- Patched in 6.3.0
- Affected Plugin
- Kirki – Freeform Page Builder, Website Builder & Customizer
- Affected Version
<= 6.2.5- CVSS
- 8.8High
- Weakness type
- CWE-502 · Deserialization of Untrusted Data
- CVE
CVE-2026-75891
At a glance
CVE-2026-75891 is a high-severity Deserialization of Untrusted Data vulnerability in the Kirki WordPress plugin, affecting versions <= 6.2.5. It carries a CVSS score of 8.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires an authenticated account at Subscriber level or above. The issue is fixed in version 6.3.0; sites on affected versions should update now. Disclosed October 2026, reported by daroo.
Vulnerability Overview
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.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-502: Deserialization of Untrusted Data
Kirki <= 6.2.5 carries this weakness at get-single-symbol, and reaching it takes an account at Subscriber level or above. Deserialization of untrusted data means the application reconstructs objects from input a caller controls, letting the attacker choose which classes get instantiated and what their properties hold.
A workable chain turns deserialization into file writes, deletions or code execution, depending on what the loaded classes do in their magic methods. For Kirki the fix is 6.3.0: builds <= 6.2.5 are affected, anything from 6.3.0 onward is not.
Remediation
Update to version 6.3.0, or a newer patched version
How does WordSec protect against this?
An attacker needs Subscriber access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Kirki 6.3.0 closes this, and updating the plugin is the step that ends it.
- Firewall
- Scanner
- Alerts
External References
Related records
Same weakness class
Other vulnerabilities in Kirki – Freeform Page Builder, Website Builder & Customizer
- 9.8CVE-2026-103065: Kirki RCE
CVE-2026-103065 - 9.8CVE-2026-16747: Kirki RCE
CVE-2026-16747 - 9.8CVE-2026-8206: Kirki 6.0.0 - 6.0.6 Privilege Escalation
CVE-2026-8206 - 7.5CVE-2026-107762: Kirki IDOR
CVE-2026-107762 - 7.5CVE-2026-12721: Kirki <= 6.0.12 SQL Injection
CVE-2026-12721 - 7.5CVE-2026-57726: Kirki SQL Injection
CVE-2026-57726 - 7.5CVE-2026-8073: Kirki <= 6.0.6 Limited Arbitrary File Read and Deletion
CVE-2026-8073 - 7.2CVE-2026-102173: Kirki Stored XSS
CVE-2026-102173
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