CVE-2025-2799 is a medium-severity Stored Cross-Site Scripting (XSS) vulnerability affecting the WP Event Manager plugin for WordPress, specifically the Events Calendar, Registrations, and Sell Tickets with WooCommerce components. The vulnerability arises from improper input sanitization and output escaping of the 'tag-name' parameter in all plugin versions up to and including 3.1.49. This flaw allows an authenticated attacker with administrator-level privileges to inject arbitrary malicious scripts into pages generated by the plugin. These scripts execute in the context of users who access the compromised pages, potentially leading to session hijacking, privilege escalation, or other malicious activities. The vulnerability is constrained to multi-site WordPress installations or those where the 'unfiltered_html' capability is disabled, limiting its scope somewhat. The CVSS v3.1 base score is 4.4, reflecting a network attack vector with high attack complexity and requiring high privileges but no user interaction. The impact is limited to confidentiality and integrity, with no direct availability impact. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability is classified under CWE-79, which covers improper neutralization of input during web page generation leading to XSS.

For European organizations, the impact of this vulnerability depends largely on their use of the affected WP Event Manager plugin within WordPress multi-site environments or configurations with restricted HTML filtering. Organizations running event management, ticketing, or registration systems on WordPress that utilize this plugin are at risk of targeted attacks that could compromise user sessions, steal sensitive data, or manipulate site content. This could lead to reputational damage, data breaches involving personal or payment information, and potential regulatory non-compliance under GDPR if personal data is exposed. The requirement for administrator-level access to exploit the vulnerability reduces the risk of external attackers directly exploiting it but raises concerns about insider threats or compromised admin accounts. The lack of user interaction needed means that once the malicious script is injected, any user visiting the affected pages could be impacted. Given the widespread use of WordPress and WooCommerce in Europe, especially among small to medium enterprises and event organizers, the vulnerability could have a moderate impact if exploited.

European organizations should prioritize the following specific mitigation steps: 1) Immediately audit WordPress installations to identify the presence of the WP Event Manager plugin and confirm if it is used in a multi-site setup or with unfiltered_html disabled. 2) Restrict administrator-level access strictly to trusted personnel and enforce strong authentication mechanisms such as multi-factor authentication (MFA) to reduce the risk of credential compromise. 3) Implement web application firewalls (WAFs) with custom rules to detect and block suspicious payloads targeting the 'tag-name' parameter. 4) Monitor logs for unusual administrator activity or unexpected changes in event-related pages. 5) Until an official patch is released, consider disabling or removing the plugin if feasible, or isolate the affected functionality to reduce exposure. 6) Educate administrators on the risks of XSS and the importance of sanitizing inputs when adding or editing tags. 7) Regularly update WordPress core and plugins to incorporate security fixes promptly once available. These targeted actions go beyond generic advice by focusing on access control, monitoring, and configuration specific to this vulnerability's exploitation conditions.