CVE-2026-95586 in Ultimate Addons for Contact Form 7 Plugin
Summary
by MITRE • 09/23/2026
Contributor Cross Site Scripting (XSS) in Ultimate Addons for Contact Form 7 <= 3.5.50 versions.
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Analysis
by VulDB Data Team • 09/23/2026
The vulnerability identified as Contributor Cross-Site Scripting within the Ultimate Addons for Contact Form 7 plugin, affecting versions up to and including 3.5.50, represents a significant security risk targeting users with contributor-level access or lower on WordPress installations. This flaw stems from insufficient input validation and output encoding mechanisms when handling user-supplied data that is subsequently rendered in web pages without proper sanitization. Specifically, the application fails to adequately escape special characters within fields intended for contributors, allowing malicious actors to inject executable JavaScript code into the context of other users' browsing sessions.
From a technical perspective, this vulnerability aligns with CWE-79, which classifies improper neutralization of input during web page generation known as Cross-Site Scripting. The root cause lies in the plugin's handling of form data or profile information where contributor inputs are directly embedded into HTML responses without applying necessary encoding functions such as htmlspecialchars or wp_kses_post. When a victim user with higher privileges, such as an administrator or editor, views content created by a compromised contributor account, the injected script executes within their browser context under the authority of that privileged session.
The operational impact of this vulnerability is substantial due to its potential for privilege escalation and data exfiltration. An attacker can exploit this flaw to steal administrative cookies, session tokens, or authentication credentials stored in local storage. This capability allows the attacker to hijack active sessions, effectively impersonating legitimate users with elevated permissions. Furthermore, the injected scripts can perform actions on behalf of the victim user, such as modifying site settings, creating new administrator accounts, or defacing the website interface. In many cases, this leads to a complete compromise of the WordPress installation and potentially the underlying server if further exploitation chains are developed using stolen credentials.
This vulnerability is closely associated with MITRE ATT&CK technique T1059, specifically sub-technique 007 for JavaScript execution in web browsers. The attack vector typically involves social engineering or direct access to contributor-level accounts where the attacker inputs malicious payloads into visible fields like name, email, or custom form entries that are displayed publicly or within admin dashboards. Because the vulnerability relies on user interaction and session context, it falls under the category of stored XSS if the payload is saved in the database and executed later when viewed by others, rather than reflected directly in a single request response.
Mitigation strategies must prioritize immediate patching to version 3.5.51 or higher where this issue has been resolved through enhanced input sanitization and output encoding practices. Administrators should also implement strict role-based access controls to limit the capabilities of contributor accounts wherever possible, reducing the attack surface available to potential intruders. Additionally, deploying a Web Application Firewall with robust XSS detection rules can provide an additional layer of defense by blocking malicious scripts before they reach the browser environment. Regular security audits and code reviews focusing on data handling in third-party plugins are essential for maintaining long-term resilience against such injection-based attacks.