CVE-2026-111948 in User Profile Builder Plugin
Summary
by MITRE • 10/21/2026
The User Profile Builder WordPress plugin before 4.0.1 does not escape the current page URL before outputting it in a JavaScript context on one of its admin pages, leading to Reflected Cross-Site Scripting against high-privilege users.
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Analysis
by VulDB Data Team • 10/21/2026
The vulnerability identified within the User Profile Builder WordPress plugin prior to version 4.0.1 represents a classic instance of reflected cross-site scripting stemming from insufficient input validation and output encoding in an administrative context. The core technical flaw lies in how the application handles the current page URL during its rendering process on specific admin pages. Instead of applying appropriate escaping mechanisms before injecting this data into JavaScript execution contexts, the plugin directly outputs the raw URL value. This oversight allows an attacker to manipulate the URL parameters such that malicious script payloads are embedded within them and subsequently executed by the browser when a user interacts with the compromised page.
From a technical perspective, this issue is categorized under CWE-79, which defines Improper Neutralization of Input During Web Page Generation commonly known as Cross-site Scripting. The specific vector here involves reflected XSS where the malicious payload is not stored in the database but rather passed via HTTP requests and immediately returned by the web application. Because the injection point resides within a JavaScript context on an admin page, the exploitation requires the victim to visit a specially crafted URL that triggers the execution of arbitrary client-side scripts. The lack of encoding means that special characters such as quotes or semicolons are not sanitized, allowing the attacker to break out of the intended data flow and inject executable code into the browser's runtime environment.
The operational impact of this vulnerability is significant due to its targeting high-privilege users within the WordPress ecosystem. Administrative accounts possess elevated permissions that allow for critical system modifications including user management, plugin installation, theme editing, and core configuration changes. If an attacker successfully exploits this reflected XSS flaw against a site administrator, they can execute arbitrary JavaScript in the context of the victim's session. This capability enables several severe attack scenarios such as stealing administrative cookies or authentication tokens to hijack sessions, performing unauthorized actions on behalf of the admin through cross-site request forgery techniques, redirecting users to malicious external sites for phishing purposes, or defacing the website interface. The ability to execute scripts also opens pathways for further exploitation including keylogging within the admin dashboard or exfiltrating sensitive data displayed on those pages.
This vulnerability aligns with MITRE ATT&CK technique T1059 which covers Command and Scripting Interpretation via client-side execution, specifically falling under sub-techniques related to JavaScript abuse in web browsers. The attack chain typically involves social engineering where the attacker crafts a malicious link containing the XSS payload and tricks an administrator into clicking it or loading it within their browser session while logged into the WordPress admin area. Once executed, the script operates with the same privileges as the authenticated user, effectively bypassing many traditional security controls that rely on authentication boundaries rather than content validation.
Mitigation strategies for this vulnerability are straightforward yet critical for maintaining system integrity. The primary and most effective remediation is to upgrade the User Profile Builder plugin to version 4.0.1 or later where the developers have implemented proper output encoding mechanisms. Developers must ensure that all dynamic data inserted into JavaScript contexts undergoes rigorous escaping using established libraries such as JSON.stringify for object serialization or specific HTML entity encoding functions tailored for script blocks. Additionally, implementing Content Security Policy headers can provide a layer of defense by restricting the sources from which scripts are allowed to execute, thereby mitigating the impact even if an injection occurs. Regular security audits and static code analysis tools should be employed during development to detect similar patterns where user-controlled input is directly embedded into executable contexts without adequate sanitization.