Executive brief
Ultimate Member, a popular WordPress plugin used for user profiles and memberships, contains a security flaw that allows unauthorized visitors to gain full administrative control over a website. This occurs because the plugin fails to prevent users from selecting powerful administrative roles during the registration process. If a site has a registration form with a role-selection field and custom roles with high privileges exist, an attacker can register an account and immediately take over the site, potentially leading to data theft or complete service disruption.
Technical details
The Ultimate Member plugin for WordPress suffers from an unauthenticated privilege escalation vulnerability in versions prior to 2.12.1. The root cause is a failure to filter roles with administrator-level capabilities from the selectable options in registration forms. Additionally, the plugin's default configuration disables post-registration safeguards intended to prevent account elevation. An attacker can exploit this by submitting a registration request with a role-selection field pointing to a site-defined role that possesses administrative privileges. This requires the target site to have a published registration form with a role-selection field and at least one custom role with elevated capabilities. The issue is resolved in version 2.12.1.
Affected products
- Ultimate Member Ultimate Member < 2.12.1
Timeline
- 2026-07-14: disclosed: Publicly published by WPScan
- 2026-07-31: advisory: NVD publication date
- 2026-07-14: patched: Fix released in version 2.12.1