CVE-2026-18432

Description

The Frontend Admin by DynamiApps plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 3.29.9. The vulnerability exists because `ActionUser::conditions_logic()` gates the `current_user_can('edit_user', $user_id)` authorization check behind an `is_numeric()` test, causing the check to be skipped entirely when `$user_id` is a non-numeric string — a condition that can be induced by passing a crafted value such as `1one` through the unvalidated `item_id` parameter of the unauthenticated `wp_ajax_nopriv_frontend_admin/forms/change_form` AJAX endpoint. This makes it possible for attackers to escalate privileges to administrator by obtaining a server-signed `_acf_objects` payload carrying the non-numeric user ID, which WordPress subsequently coerces to integer 1 (the default administrator), allowing the attacker to overwrite that account's password or email address. Exploitation by unauthenticated users requires a public-facing frontend user form to be configured; in all other cases a subscriber-level account is sufficient.

References

• https://plugins.trac.wordpress.org/browser/acf-frontend-form-element/tags/3.29.3/main/frontend/forms/actions/user.php#L565
• https://plugins.trac.wordpress.org/browser/acf-frontend-form-element/tags/3.29.3/main/frontend/forms/actions/user.php#L680
• https://plugins.trac.wordpress.org/browser/acf-frontend-form-element/tags/3.29.3/main/frontend/forms/classes/display.php#L1654
• https://plugins.trac.wordpress.org/browser/acf-frontend-form-element/tags/3.29.3/main/frontend/forms/classes/display.php#L1953
• https://plugins.trac.wordpress.org/browser/acf-frontend-form-element/tags/3.29.3/main/frontend/forms/classes/display.php#L37