CVE-2020-36155

The Ultimate Member plugin before version 2.1.12 contained an unauthenticated privilege escalation vulnerability in its registration process. An attacker could manipulate array parameters submitted during user registration to modify sensitive user metadata fields, including wp_capabilities, which controls user roles and permissions. Because the registration form accepted and processed arbitrary metadata without proper validation, an attacker could grant themselves administrator access by injecting wp_capabilities[administrator] during signup.

Based on public CVE data (MITRE/NVD).