CVE-2025-50017 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the WordPress plugin 'WP Voting Contest' developed by Matt. This vulnerability arises due to improper neutralization of user-supplied input during web page generation, allowing malicious scripts to be stored and subsequently executed in the context of users visiting the affected site. The vulnerability impacts all versions of WP Voting Contest up to and including version 5.8. Exploitation requires an attacker with at least some level of authenticated access (as indicated by the CVSS vector requiring privileges and user interaction), who can inject malicious payloads into the voting contest input fields or other user input areas that are not properly sanitized. When other users, including administrators or privileged users, view the affected pages, the malicious script executes, potentially leading to session hijacking, privilege escalation, or redirection to malicious sites. The CVSS 3.1 base score is 5.9 (medium severity), reflecting a network attack vector with low attack complexity but requiring privileges and user interaction, and resulting in limited confidentiality, integrity, and availability impacts. The vulnerability has not yet been observed exploited in the wild, and no patches or fixes have been published as of the date of analysis. Stored XSS vulnerabilities are particularly dangerous in multi-user environments such as WordPress sites, where they can be leveraged to compromise administrative accounts or spread malware to site visitors. Given the plugin's role in managing voting contests, the vulnerability could also be abused to manipulate contest outcomes or disrupt user trust in the platform.

For European organizations using the WP Voting Contest plugin, this vulnerability poses several risks. Organizations running community engagement, marketing, or promotional campaigns via WordPress voting contests could face reputational damage if attackers exploit the vulnerability to inject malicious scripts. This could lead to theft of user credentials, unauthorized actions performed on behalf of users, or defacement of contest pages. The integrity of contest results may be compromised, undermining trust in the organization’s digital services. Additionally, if administrative users are targeted, attackers could gain elevated privileges, potentially leading to broader site compromise. The availability impact is limited but could manifest as denial of service through script-based disruptions. Since many European organizations rely on WordPress for public-facing websites, especially small and medium enterprises (SMEs) and non-profits that often use free or low-cost plugins, the risk is non-trivial. However, the requirement for attacker privileges and user interaction reduces the likelihood of widespread automated exploitation. Nonetheless, targeted attacks against politically sensitive campaigns, NGOs, or commercial promotions in Europe could leverage this vulnerability to cause harm.

1. Immediate mitigation involves restricting plugin usage to trusted users only and limiting the number of users with privileges to submit or manage voting content. 2. Implement Web Application Firewall (WAF) rules specifically designed to detect and block typical XSS payloads targeting the voting contest input fields. 3. Apply strict Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected pages. 4. Conduct manual code review and sanitize all user inputs in the WP Voting Contest plugin, especially those that are rendered without proper escaping or encoding. 5. Monitor logs for unusual activity related to voting contest submissions or administrative actions. 6. Until an official patch is released, consider disabling or removing the WP Voting Contest plugin if it is not critical to operations. 7. Educate site administrators and users about the risks of clicking on suspicious links or interacting with untrusted content within the voting contest. 8. Regularly update WordPress core and plugins to the latest versions once patches become available. 9. Employ security plugins that provide XSS protection and input validation enhancements.