CVE-2025-13961 is a stored Cross-Site Scripting (XSS) vulnerability identified in the Data Visualizer plugin for WordPress, developed by subhransu-sekhar. This vulnerability exists in all plugin versions up to and including 1.1 due to improper neutralization of input during web page generation (CWE-79). Specifically, the plugin's 'visualize' shortcode fails to adequately sanitize and escape user-supplied attributes, allowing authenticated users with contributor-level permissions or higher to inject arbitrary JavaScript code into pages. When other users access these pages, the injected scripts execute in their browsers, potentially compromising session tokens, redirecting users, or performing actions on their behalf. The vulnerability has a CVSS 3.1 base score of 6.4, reflecting medium severity, with an attack vector of network (remote), low attack complexity, requiring privileges (contributor or above), no user interaction, and a scope change due to affecting other users. No public exploits are currently known, and no patches have been released at the time of publication. The vulnerability is particularly concerning in multi-user WordPress environments where contributors can add content but are not fully trusted. The stored nature of the XSS means the malicious payload persists in the site content, increasing risk. The lack of output escaping and input sanitization in the shortcode processing is the root cause, highlighting a common web application security weakness. This vulnerability underscores the importance of strict input validation and output encoding in WordPress plugins that process user-generated content.

For European organizations, this vulnerability poses a significant risk to WordPress-based websites that utilize the Data Visualizer plugin, especially those with multiple contributors or editors. Exploitation could lead to session hijacking, unauthorized actions performed on behalf of users, defacement, or distribution of malware via injected scripts. This can damage organizational reputation, lead to data breaches, and cause compliance issues under regulations such as GDPR if personal data is compromised. The medium severity score reflects that while the impact on confidentiality and integrity is notable, availability is not affected. The requirement for contributor-level access limits the attack surface but does not eliminate risk, as insider threats or compromised contributor accounts can be leveraged. European organizations with public-facing WordPress sites, particularly in sectors like media, education, and government, where contributor roles are common, are at elevated risk. The persistence of the injected scripts increases the window of exposure, potentially affecting many users. Additionally, the cross-site scripting vulnerability could be chained with other attacks to escalate privileges or exfiltrate sensitive data.

European organizations should immediately audit their WordPress installations to identify the presence of the Data Visualizer plugin and verify its version. Until an official patch is released, restrict contributor-level permissions to trusted users only and consider temporarily disabling the plugin if feasible. Implement Web Application Firewall (WAF) rules to detect and block malicious payloads targeting the 'visualize' shortcode parameters. Conduct thorough input validation and output encoding for any custom shortcodes or plugins in use. Monitor website content for unexpected script injections or anomalies. Educate contributors about the risks of uploading untrusted content or scripts. Once a patch becomes available, prioritize prompt application. Additionally, implement Content Security Policy (CSP) headers to limit the impact of potential XSS by restricting script sources. Regularly review user roles and permissions to minimize the number of users with contributor or higher access. Employ security plugins that can scan for XSS vulnerabilities and malicious content. Maintain comprehensive backups to enable rapid recovery if exploitation occurs.