CVE-2026-115807 in User Profile Builder Plugin
Summary
by MITRE • 10/24/2026
The User Profile Builder – Beautiful User Registration Forms, User Profiles & User Role Editor plugin for WordPress is vulnerable to Limited Privilege Escalation in all versions up to, and including, 4.0.3. This is due to the Gutenberg Register block passing the attacker-controlled Assigned Role attribute directly into the `[wppb-register]` shortcode without server-side authorization. The role guard in the form builder only downgrades roles that carry the manage_options or remove_users capability, leaving the Editor role and other privileged non-Administrator roles completely unrestricted. This makes it possible for authenticated attackers with Author-level access and above to create new WordPress accounts bearing the Editor role (or any other role that lacks the two guarded capabilities).
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Analysis
by VulDB Data Team • 10/24/2026
The User Profile Builder plugin for WordPress, specifically versions up through 4.0.3, contains a critical security flaw classified as Limited Privilege Escalation. This vulnerability stems from an insufficient authorization check within the Gutenberg Register block functionality. The core issue arises when the plugin processes the Assigned Role attribute provided by the user interface and passes it directly into the underlying wppb-register shortcode without performing adequate server-side validation of the requesting user's permissions relative to the role being assigned.
The technical mechanism of this flaw involves a gap in the application logic designed to prevent users from assigning roles higher than their own or restricted administrative levels. The existing security controls, often referred to as role guards, are implemented with overly permissive criteria. Specifically, these guards only restrict the assignment of roles that possess either the manage_options capability or the remove_users capability. This binary check fails to account for other privileged roles within the WordPress ecosystem, such as Editor, which do not inherently hold those specific capabilities but still grant significant control over site content and user management functions.
As a direct result of this logic error, authenticated attackers with Author-level access or higher can exploit this weakness to escalate their privileges. By manipulating the Assigned Role attribute in the registration form configuration, an attacker can create new WordPress accounts that are assigned the Editor role or any other privileged non-Administrator role. This effectively bypasses the intended hierarchy where only Administrators should be able to assign high-level roles, allowing lower-tier users to expand their influence and control over the website environment beyond what was originally permitted by their initial account level.
The operational impact of this vulnerability is significant for WordPress site administrators relying on User Profile Builder for user registration workflows. It allows malicious actors who have already gained authenticated access at a moderate privilege level to establish persistent backdoors or administrative-like accounts that are harder to detect than standard low-privilege accounts. These escalated accounts can be used to modify content, manage other users, and potentially pivot further into the system if additional vulnerabilities exist within plugins accessible by Editors. This undermines the principle of least privilege and compromises the integrity of user management systems on affected sites.
To mitigate this risk, site administrators should immediately update the User Profile Builder plugin to version 4.0.4 or later, where these authorization checks have been hardened to properly validate role assignments against a comprehensive list of capabilities rather than just two specific ones. In environments where immediate patching is not feasible, it is advisable to restrict access to the Gutenberg editor and registration form settings to Administrators only. Additionally, implementing strict monitoring for new user account creations with elevated roles can help in detecting potential exploitation attempts early. This vulnerability aligns with CWE-269 Improper Privilege Management and maps to ATT&CK techniques related to Account Manipulation and Privilege Escalation within the WordPress ecosystem.