CVE-2025-11859 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Paypal Donation Shortcode plugin for WordPress, developed by coenjacobs. This vulnerability affects all versions up to and including 0.1. The root cause is the plugin's failure to properly sanitize user-supplied input in the 'title' and 'text' parameters of the 'paypal' shortcode. Authenticated users with contributor-level access or higher can exploit this flaw by injecting arbitrary JavaScript code into pages or posts that utilize the shortcode. Because the malicious script is stored persistently in the WordPress database, it executes every time a user accesses the infected page, potentially compromising the confidentiality and integrity of user sessions and data. The CVSS 3.1 base score of 6.4 reflects a medium severity rating, with an attack vector over the network, low attack complexity, privileges required at the contributor level, no user interaction needed, and a scope change indicating that the vulnerability can affect components beyond the vulnerable plugin. Although no public exploits have been reported yet, the vulnerability poses a significant risk, especially in environments where multiple users have contributor or higher privileges. The vulnerability is categorized under CWE-79, which is a common and well-understood class of input validation flaws leading to XSS. Given WordPress's widespread use in Europe, particularly for e-commerce and donation platforms, this vulnerability could be leveraged to perform session hijacking, defacement, or phishing attacks, undermining user trust and potentially leading to data breaches or financial fraud.

For European organizations, the impact of CVE-2025-11859 can be substantial, especially for those operating WordPress sites that utilize the Paypal Donation Shortcode plugin. Exploitation allows attackers with contributor-level access to inject malicious scripts that execute in the browsers of site visitors and administrators. This can lead to session hijacking, theft of sensitive information such as credentials or payment data, unauthorized actions performed on behalf of users, and reputational damage. Non-technical users and site administrators may be unaware of the compromise, increasing the risk of prolonged exploitation. Organizations involved in charitable donations, e-commerce, or community engagement are particularly vulnerable due to the plugin's donation-related functionality. Additionally, the vulnerability could be leveraged as a foothold for further attacks within the network, especially if administrative accounts are compromised. The medium severity rating suggests a moderate but non-negligible risk, warranting timely remediation to prevent escalation. Given the interconnected nature of European digital infrastructure and GDPR requirements for data protection, exploitation could also lead to regulatory penalties and loss of customer trust.

To mitigate CVE-2025-11859, European organizations should first verify if they are using the Paypal Donation Shortcode plugin and identify the installed version. Since no official patch links are provided, immediate mitigation steps include restricting contributor-level access to trusted users only and auditing existing contributors for suspicious activity. Implementing Web Application Firewall (WAF) rules that detect and block malicious script payloads in the 'title' and 'text' parameters can reduce exploitation risk. Site administrators should enforce strict input validation and output encoding on all shortcode parameters, potentially by customizing the plugin or applying security plugins that sanitize inputs. Regularly scanning WordPress installations with security tools for XSS vulnerabilities and monitoring logs for unusual behavior is recommended. Additionally, educating content contributors about safe input practices and limiting the use of shortcodes to trusted users can reduce attack surface. Organizations should also prepare incident response plans to quickly address any detected exploitation. Finally, monitoring the plugin vendor's communications for official patches or updates is critical to apply permanent fixes once available.