CVE-2026-104748: SimpleForm privilege escalation vulnerability
critical 9.8 published 2026-10-14 · updated 2026-10-15
- Affected versions
- 3.10.0 and older
- Fixed in
- 3.10.1 *
- Latest version
- 3.11.0
- Severity
- Critical · CVSS 9.8
- Active installs
- 30+
- Type
- Privilege escalation
* 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 SimpleForm to 3.10.1 or newer (the latest is 3.11.0): 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 SimpleForm issue.
With WP-CLI:
wp plugin get simple-form --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 SimpleForm – Form Maker to Chat Apps with Quiz, Poll and Multi Lead Notifications plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 3.10.0 This is due to the `wp_ajax_nopriv_simpleform_wp_register` AJAX action lacking any capability check for role assignment and the `save_custom_fields_to_user_meta()` function using an exclusion list that omits `wp_capabilities`, combined with `get_form_settings()` returning a hard-coded defaults array that unconditionally enables meta writing regardless of the supplied `form_id`. This makes it possible for unauthenticated attackers to create a new Administrator-level WordPress account by supplying `wp_capabilities[administrator]=1` alongside standard registration fields. The nonce required by the endpoint is publicly emitted into the `front_end_data` JavaScript object on every front-end page via `wp_enqueue_scripts`, making it trivially obtainable by any unauthenticated visitor before submitting the malicious request.
References
- NVD CVE-2026-104748 nvd.nist.gov
- Wordfence advisory www.wordfence.com
- Code change (fix) plugins.trac.wordpress.org
- plugins.svn.wordpress.org plugins.svn.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/simple-form (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.