CVE-2026-94391 in Ultimate FAQ Plugin
Summary
by MITRE • 09/23/2026
Contributor Cross Site Scripting (XSS) in Ultimate FAQ <= 2.4.14 versions.
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Analysis
by VulDB Data Team • 09/23/2026
The vulnerability identified as Contributor Cross-Site Scripting within the Ultimate FAQ plugin for WordPress, affecting versions up to and including 2.4.14, represents a significant security risk associated with insufficient input validation on user-facing roles that possess limited privileges. This specific flaw allows authenticated users who have been assigned the contributor role to inject malicious JavaScript code into web pages viewed by other users or administrators. Unlike vulnerabilities requiring administrative access, this issue exploits the trust relationship between the application and lower-privileged accounts, which are often granted more freedom in content creation but may lack rigorous sanitization of their inputs before storage and subsequent rendering.
From a technical perspective, the root cause lies in the improper neutralization of special elements used by an input vector, commonly categorized under CWE-79: Improper Neutralization of Input During Web Page Generation Cross-site Scripting. When a contributor submits content containing script tags or event handlers such as onerror or onload attributes, the application fails to adequately escape these characters before storing them in the database and displaying them back to users. This lack of output encoding allows the browser to interpret the injected payload as executable code rather than plain text data. The vulnerability is particularly dangerous because it does not require complex exploitation techniques; an attacker simply needs a valid contributor account, which can sometimes be obtained through social engineering or by exploiting other minor configuration weaknesses in WordPress installations where user registration is open.
The operational impact of this cross-site scripting flaw extends beyond simple defacement or annoyance. Attackers leveraging this vulnerability can execute arbitrary JavaScript in the context of the victim's browser session. This capability enables a range of malicious activities including session hijacking, where the attacker steals authentication cookies to impersonate legitimate users; credential harvesting by creating fake login forms that capture usernames and passwords; keylogging to record sensitive information typed into other applications on the same domain; or redirecting victims to phishing sites designed to steal further data. Because the script executes with the privileges of the victim, if an administrator views a page containing the malicious payload, their administrative session could be compromised, potentially leading to full site takeover and compromise of all stored data including customer information and proprietary content.
This vulnerability aligns with several entries in the MITRE ATT&CK framework for enterprise security. It is primarily associated with T1059: Command and Scripting Interpreter, specifically through JavaScript execution within a web browser context. Furthermore, it facilitates T1078: Valid Accounts, as the attacker utilizes legitimate contributor credentials to gain initial access. The subsequent actions such as stealing cookies or capturing keystrokes fall under T1539: Steal Web Session Cookie and T1056: Input Capture respectively. Understanding these mappings helps security teams prioritize remediation efforts based on the potential for lateral movement and data exfiltration within their specific environment.
To mitigate this vulnerability, immediate action is required to update the Ultimate FAQ plugin to version 2.4.15 or later where the input validation logic has been corrected. For organizations unable to patch immediately due to compatibility concerns with other plugins, a temporary workaround involves restricting the contributor role's capabilities using security plugins that enforce stricter content filtering rules on specific post types. Additionally, implementing a Content Security Policy header can help mitigate the impact of successful XSS attacks by restricting the sources from which scripts are allowed to load and execute, thereby preventing many common exploitation techniques even if the injection occurs. Regular auditing of user roles and ensuring that only trusted individuals hold contributor or higher privileges is also essential for maintaining overall application security posture.