CVE-2026-115806: Prime Mover PHP object injection vulnerability
critical 9.8 published 2026-10-24 · updated 2026-10-29
- Affected versions
- 2.2.1 and older
- Fixed in
- 2.2.2 *
- Latest version
- 2.2.2
- Severity
- Critical · CVSS 9.8
- Active installs
- 10,000+
- 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: None. No account or login is needed.
CVSS vector (score by Wordfence): CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
What to do now
- Update Prime Mover to 2.2.2 or newer: 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 Prime Mover issue.
With WP-CLI:
wp plugin get prime-mover --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 Prime Mover – Backup and Migration plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 2.2.1 via deserialization of untrusted input in the migration search-and-replace routine (recursiveUnserializeReplace()). An unauthenticated attacker can store a crafted, base64-encoded serialized object in wp_comments.comment_content through the standard comment-submission endpoint (wp-comments-post.php). When an administrator subsequently performs a routine Prime Mover export or restore, the plugin base64-decodes that stored value and passes it to unserialize() with no allowed_classes restriction. A Property-Oriented Programming (POP) chain is present in the plugin's own bundled Freemius library (FS_Clone_Manager::__set → FS_Option_Manager::set_option → store() → update_option()), so no additional plugin or theme is required — the plugin ships the gadget itself.
References
- NVD CVE-2026-115806 nvd.nist.gov
- Wordfence advisory www.wordfence.com
- Plugin source 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/prime-mover (Plugins API), fetched 2026-11-04.
- 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.