CVE-2025-11817 identifies a stored Cross-Site Scripting (XSS) vulnerability in the Simple Tableau Viz plugin for WordPress, which is used to embed Tableau visualizations via a shortcode. The vulnerability exists due to insufficient sanitization and escaping of user-supplied attributes in the 'tableau' shortcode, allowing authenticated users with contributor-level permissions or higher to inject arbitrary JavaScript code into pages. When other users access these pages, the malicious scripts execute in their browsers, potentially compromising session tokens, cookies, or enabling unauthorized actions within the context of the victim's session. The vulnerability is exploitable remotely over the network without user interaction, but requires the attacker to have contributor or higher privileges, which is a moderate barrier. The CVSS 3.1 base score of 6.4 reflects a medium severity, with confidentiality and integrity impacts but no availability impact. The vulnerability affects all versions of the plugin up to and including 2.0, with no patches currently available. No known exploits have been reported in the wild, but the presence of this vulnerability in a widely used WordPress plugin makes it a notable risk. The issue stems from a classic CWE-79 flaw, emphasizing the need for proper input validation and output encoding in web applications to prevent script injection attacks.

For European organizations, this vulnerability could lead to unauthorized access to user sessions, data theft, or manipulation of website content, especially on sites that allow multiple contributors to publish content. The exploitation could result in reputational damage, loss of customer trust, and potential regulatory consequences under GDPR if personal data is compromised. Since WordPress is widely used across Europe for corporate, governmental, and non-profit websites, the risk is significant where the Simple Tableau Viz plugin is deployed. Attackers exploiting this vulnerability could pivot to further attacks within the network or use compromised accounts to escalate privileges. The medium severity indicates a moderate but tangible risk, particularly for organizations with collaborative content management workflows. The lack of known exploits in the wild suggests a window of opportunity for defenders to remediate before widespread attacks occur.

Organizations should immediately audit their WordPress installations to identify the presence of the Simple Tableau Viz plugin and verify the version in use. Until an official patch is released, restrict contributor-level and higher privileges to trusted users only, minimizing the risk of malicious shortcode injection. Implement Web Application Firewall (WAF) rules to detect and block suspicious shortcode attribute patterns or script tags. Employ Content Security Policy (CSP) headers to limit the execution of unauthorized scripts in browsers. Regularly monitor website content for unauthorized changes or injected scripts. Educate content contributors about the risks of injecting untrusted content. Once a patch becomes available, apply it promptly. Additionally, consider disabling or replacing the plugin if it is not essential to reduce the attack surface.