CVE-2026-0844 in Simple User Registration Plugin
Summary
by MITRE • 01/28/2026
The Simple User Registration plugin for WordPress is vulnerable to privilege escalation in versions up to, and including, 6.7 due to insufficient restriction on the 'profile_save_field' function. This makes it possible for authenticated attackers, with minimal permissions such as a subscriber, to modify their user role by supplying the 'wp_capabilities' parameter during a profile update.
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Analysis
by VulDB Data Team • 01/29/2026
The vulnerability identified as CVE-2026-0844 affects the Simple User Registration plugin for WordPress, specifically impacting versions up to and including 6.7. This represents a critical privilege escalation flaw that undermines the fundamental security model of WordPress user management systems. The vulnerability resides within the 'profile_save_field' function which fails to properly validate or restrict user input parameters during profile update operations. Attackers with minimal privileges such as subscribers can exploit this weakness to elevate their access rights within the WordPress environment.
The technical flaw stems from inadequate input validation and authorization checks within the plugin's user profile management system. When an authenticated user submits a profile update request, the system does not sufficiently verify whether the requesting user has the authority to modify capability-related parameters. The 'wp_capabilities' parameter serves as a direct vector for role manipulation, allowing attackers to assign themselves higher privileges without proper authorization. This vulnerability directly violates the principle of least privilege and demonstrates a critical failure in the plugin's access control implementation.
The operational impact of this vulnerability extends beyond simple privilege escalation, creating potential pathways for further attacks within the WordPress ecosystem. An attacker who successfully exploits this vulnerability can transition from a subscriber account to roles such as administrator or editor, gaining access to sensitive administrative functions including plugin management, theme customization, content modification, and user management. This escalation can lead to complete system compromise, data theft, or unauthorized modification of website content. The vulnerability affects any WordPress site using the affected plugin version, making it particularly dangerous given the widespread adoption of WordPress and its plugins.
From a cybersecurity perspective, this vulnerability maps directly to CWE-285 (Improper Authorization) and aligns with ATT&CK technique T1078 (Valid Accounts) and T1548.1 (Abuse Elevation Control Mechanism). The flaw represents a failure in the authorization controls that should prevent users from modifying their own capabilities, particularly when those modifications could result in privilege escalation. Organizations should immediately update to the patched version of the Simple User Registration plugin or implement temporary mitigations such as restricting user capabilities through wp-config.php modifications. Additionally, monitoring for unusual profile update activities and implementing role-based access controls can help detect potential exploitation attempts. The vulnerability underscores the importance of thorough input validation and proper authorization checks in web applications, particularly in user management systems where privilege levels directly impact system security.