CVE-2026-104734: Kirki PHP object injection vulnerability
high 7.2 published 2026-10-17 · updated 2026-10-19
- Affected versions
- 6.3.2 and older
- Fixed in
- 6.4.0 *
- Latest version
- 6.4.1
- Severity
- High · CVSS 7.2
- Active installs
- 400,000+
- Type
- PHP object injection
* The source does not name a fixed version; this is the first wordpress.org release after the last affected version.
What an attacker needs
- Access: An administrator account (or a hijacked admin session).
CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
What to do now
- Update Kirki to 6.4.0 or newer (the latest is 6.4.1): Dashboard → Updates, or Plugins → “update now”.
- If you cannot update right away, deactivate it until you can.
- Turn on auto-updates for it: Plugins → “Enable auto-updates” on its row.
- Not sure which version you run? Check your version against every known Kirki issue.
With WP-CLI:
wp plugin get kirki --field=version. - If you ran an affected version and something looks off (new admin users, spam pages, redirects), run the free scan below.
The advisory
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.
References
- NVD CVE-2026-104734 nvd.nist.gov
- Wordfence advisory www.wordfence.com
- Code change (fix) plugins.trac.wordpress.org
- Plugin source plugins.trac.wordpress.org
Related
Ran an affected version? Check your site for signs of a hack
The free scan reads the public side of your site and looks for spam pages, hidden redirects, injected scripts and blacklist entries. No login, no install, about a minute.
Where this data comes from
- CVE record, score and references: NIST National Vulnerability Database (NVD), checked 2026-11-04. This product uses data from the NVD API but is not endorsed or certified by the NVD.
- Versions and install counts: wordpress.org/plugins/kirki (Plugins API), fetched 2026-11-01.
- The summary, “what an attacker needs” and “what to do” sections are our plain-English reading of the record and the plugin's release history; the quoted description is the record's own text. Spot an error? Email Daniel.