CVE-2026-93772 in wpForo Forum Plugin
Summary
by MITRE • 09/23/2026
Subscriber Cross Site Scripting (XSS) in wpForo Forum <= 3.1.5 versions.
VulDB is the best source for vulnerability data and more expert information about this specific topic.
Analysis
by VulDB Data Team • 09/23/2026
The vulnerability identified as Subscriber Cross-Site Scripting within the wpForo WordPress plugin, affecting versions up to and including 3.1.5, represents a significant security risk for web applications that rely on this forum software. This flaw is classified under CWE-79, which denotes Improper Neutralization of Input During Web Page Generation commonly known as Cross-Site Scripting. The core technical issue stems from the application's failure to adequately sanitize or encode user-supplied input before rendering it in HTML contexts. Specifically, when a registered subscriber interacts with certain features of the forum such as posting messages, editing profiles, or utilizing specific widgets, malicious script payloads can be injected into the data stream. Because wpForo processes this content and displays it back to other users without proper validation against executable code, an attacker can execute arbitrary JavaScript in the context of a victim's browser session.
From an operational perspective, this vulnerability allows for a stored or reflected XSS attack depending on where the input is persisted within the database. If the malicious script is saved as part of a forum post or profile information, it becomes persistent and will trigger every time another user views that content. This persistence amplifies the severity because it does not require complex social engineering to trick a specific target into clicking a unique link; rather, any visitor to the affected page can become an victim. The attacker gains the ability to perform actions on behalf of the authenticated subscriber, such as changing account settings, posting new messages that appear legitimate, or stealing sensitive data like session cookies and authentication tokens. This capability effectively compromises the confidentiality and integrity of user accounts within the forum ecosystem.
The impact extends beyond individual account compromise due to the potential for broader system manipulation if combined with other vulnerabilities or through cross-site request forgery techniques facilitated by stolen credentials. Attackers can use the injected scripts to redirect users to phishing sites, deface the website's appearance, or harvest sensitive information from local storage and cookies that contain session identifiers. In environments where wpForo is integrated with broader WordPress functionalities, this breach could potentially serve as a pivot point for further attacks against the underlying content management system if privilege escalation paths exist. The trust relationship between users and the platform is fundamentally broken when malicious scripts can be injected by low-privilege subscribers, undermining the integrity of community interactions and data exchange.
Mitigation strategies must focus on both immediate remediation and long-term defensive coding practices. Administrators should immediately update wpForo to version 3.1.6 or later where this issue has been addressed through improved input validation and output encoding mechanisms. For systems that cannot be updated instantly, implementing a Web Application Firewall can provide temporary protection by filtering out known malicious patterns in HTTP requests before they reach the application logic. Additionally, developers should enforce strict Content Security Policy headers to restrict the execution of inline scripts and limit sources from which external resources can be loaded, thereby reducing the impact even if an injection attempt succeeds. From a development standpoint, adhering to OWASP guidelines for input validation is critical; all user inputs must be treated as untrusted data until proven otherwise through rigorous sanitization processes that strip or encode special characters before they are rendered in HTML contexts.
This vulnerability aligns with MITRE ATT&CK technique T1059 which covers Command and Scripting Interpreter execution, specifically JavaScript within a browser environment. It also relates to the initial access vector of phishing if used for credential harvesting via redirected login pages. Security teams should monitor server logs for unusual patterns in POST requests that contain encoded script tags or event handlers such as onerror or onload attributes embedded in form submissions. Regular security audits and penetration testing focused on input validation weaknesses are essential to prevent similar flaws from being introduced during future development cycles. Ensuring that the principle of least privilege is applied to subscriber roles can also limit the blast radius if a vulnerability like this were to be exploited, by restricting what data subscribers can modify or view within the forum structure.