CVE-2025-14138 is a reflected Cross-Site Scripting (XSS) vulnerability identified in the WPLG Default Mail From plugin for WordPress, affecting all versions up to and including 1.0.0. The vulnerability stems from improper neutralization of input during web page generation, specifically through the $_SERVER['PHP_SELF'] variable, which is not adequately sanitized or escaped before being output. This allows unauthenticated attackers to craft malicious URLs containing embedded scripts that, when clicked by a user, execute in the context of the victim’s browser. The attack does not require authentication but does require user interaction (clicking a malicious link). The vulnerability impacts confidentiality and integrity by potentially allowing theft of session cookies, user credentials, or execution of unauthorized actions on behalf of the user. The CVSS v3.1 score is 6.1, reflecting medium severity with network attack vector, low attack complexity, no privileges required, and user interaction needed. No patches are currently available, and no known exploits have been observed in the wild. The vulnerability is classified under CWE-79, indicating improper input neutralization leading to XSS. This flaw is particularly dangerous in WordPress environments where the plugin is active, as it can be leveraged to compromise site visitors or administrators.

For European organizations, the impact of this vulnerability can be significant, especially for those relying on WordPress websites with the WPLG Default Mail From plugin installed. Successful exploitation can lead to theft of sensitive user data such as authentication tokens or personal information, session hijacking, and unauthorized actions performed in the context of the victim user. This can undermine user trust, lead to data breaches, and potentially facilitate further attacks such as privilege escalation or malware distribution. Public-facing websites, e-commerce platforms, and portals handling sensitive customer data are particularly at risk. The reflected nature of the XSS means attackers must lure users into clicking malicious links, which can be done via phishing campaigns targeting European users. The medium severity score indicates a moderate but actionable risk that can disrupt confidentiality and integrity without affecting availability. Organizations in Europe with high WordPress usage and reliance on this plugin should consider the threat a priority for remediation to avoid reputational damage and regulatory consequences under GDPR.

1. Monitor for official patches or updates from the wpletsgo vendor and apply them immediately once available. 2. In the absence of patches, implement Web Application Firewalls (WAFs) with rules specifically designed to detect and block reflected XSS payloads targeting the $_SERVER['PHP_SELF'] parameter. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 4. Review and sanitize all user-controllable inputs in custom WordPress themes or plugins, especially those that output server variables. 5. Educate users and staff about phishing risks and the dangers of clicking suspicious links. 6. Conduct regular security audits and penetration tests focusing on XSS vulnerabilities in WordPress environments. 7. Consider temporarily disabling or replacing the vulnerable plugin if immediate patching is not feasible. 8. Use security plugins that provide XSS protection and input validation enhancements for WordPress. These measures collectively reduce the risk of exploitation and limit the impact if an attack occurs.