CVE-2025-11764 is a stored cross-site scripting (XSS) vulnerability identified in the Shortcodes Bootstrap plugin for WordPress, developed by fastmover. The vulnerability exists due to improper neutralization of input during web page generation, specifically within the 'type' parameter of the [notification] shortcode. All versions up to and including 1.1 are affected. The root cause is the lack of proper input sanitization and output escaping, allowing authenticated users with contributor-level privileges or higher to inject arbitrary JavaScript code into pages. When other users access these pages, the injected scripts execute in their browsers, potentially leading to session hijacking, privilege escalation, or unauthorized actions within the WordPress environment. The vulnerability has a CVSS 3.1 base score of 6.4, indicating medium severity, with an attack vector of network (remote), low attack complexity, requiring privileges (PR:L), no user interaction, and a scope change (S:C). The impact affects confidentiality and integrity but not availability. No public exploits have been reported yet, but the vulnerability's nature makes it a candidate for exploitation in targeted attacks. The plugin is widely used in WordPress sites for adding customizable shortcodes, making the vulnerability relevant for many websites relying on this functionality. The vulnerability was published on November 21, 2025, with the initial reservation on October 14, 2025. No official patches or updates have been linked yet, so mitigation relies on access control and input validation measures.

For European organizations, this vulnerability poses a risk primarily to websites running WordPress with the Shortcodes Bootstrap plugin installed. Exploitation can lead to unauthorized script execution, compromising user sessions, leaking sensitive information, or enabling further attacks such as privilege escalation or defacement. This can damage organizational reputation, lead to data breaches, and violate data protection regulations such as GDPR if personal data is exposed. The medium severity score reflects moderate risk, but the requirement for contributor-level access limits exploitation to insiders or compromised accounts. However, many organizations allow contributors or editors to manage content, increasing the attack surface. The vulnerability's ability to affect confidentiality and integrity without availability impact means attackers can stealthily manipulate site content or user data. Given the widespread use of WordPress in Europe, especially among SMEs and public sector websites, the threat is significant. Additionally, sectors with high regulatory scrutiny, such as finance, healthcare, and government, may face increased compliance risks if exploited.

1. Immediate mitigation includes restricting contributor-level access to trusted users only, minimizing the risk of malicious script injection. 2. Implement web application firewalls (WAFs) with custom rules to detect and block suspicious shortcode parameters or script payloads targeting the 'type' parameter. 3. Monitor WordPress logs and user activity for unusual changes or content injections related to the Shortcodes Bootstrap plugin. 4. Apply manual input validation and output escaping in the shortcode handling code if possible, as a temporary fix until an official patch is released. 5. Regularly check for updates from the plugin vendor and apply patches promptly once available. 6. Educate content contributors about the risks of injecting untrusted content and enforce content review workflows. 7. Use Content Security Policy (CSP) headers to restrict script execution sources, mitigating impact if exploitation occurs. 8. Conduct security audits of WordPress plugins and remove or replace plugins that are no longer maintained or vulnerable. These steps go beyond generic advice by focusing on access control, monitoring, and layered defenses specific to this vulnerability.