CVE-2026-75891: Kirki PHP object injection vulnerability
high 8.8 published 2026-10-27 · updated 2026-10-29
- Affected versions
- 6.2.5 and older
- Fixed in
- 6.3.0 *
- Latest version
- 6.4.1
- Severity
- High · CVSS 8.8
- 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: A logged-in account with Subscriber-level access or higher.
CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
What to do now
- Update Kirki to 6.3.0 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 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.
References
- NVD CVE-2026-75891 nvd.nist.gov
- Wordfence advisory www.wordfence.com
- Code change (fix) plugins.trac.wordpress.org
Related
Ran an affected version? Check your site for signs of a hack
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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.