CVE-2025-9057 is a medium-severity Stored Cross-Site Scripting (XSS) vulnerability affecting the Biagiotti Core plugin for WordPress, developed by Mikado Themes. This vulnerability exists in all versions up to and including 2.1.3. The root cause is insufficient input sanitization and output escaping of user-supplied shortcode attributes. Authenticated attackers with contributor-level or higher permissions can exploit this flaw by injecting malicious JavaScript code into pages via shortcodes. Because the injected scripts are stored and rendered whenever any user accesses the compromised page, this can lead to persistent XSS attacks. The vulnerability has a CVSS 3.1 base score of 6.4, reflecting its medium severity with network attack vector, low attack complexity, and requiring privileges of a contributor or above but no user interaction. The scope is changed, indicating that the vulnerability affects resources beyond the initially vulnerable component. The impact includes limited confidentiality and integrity loss, as attackers can execute arbitrary scripts in the context of the victim's browser, potentially stealing session tokens, performing actions on behalf of users, or defacing content. Availability is not impacted. No known exploits are currently reported in the wild, and no official patches have been linked yet. The vulnerability was reserved in mid-August 2025 and published in early September 2025. This issue is categorized under CWE-79, which relates to improper neutralization of input during web page generation, a common vector for XSS attacks in web applications. Given that WordPress is widely used across Europe and Biagiotti Core is a popular theme plugin, this vulnerability poses a significant risk to websites using this plugin without updated versions or mitigations in place.

For European organizations, especially those relying on WordPress websites with the Biagiotti Core plugin, this vulnerability can lead to unauthorized script execution in users' browsers. This can result in session hijacking, unauthorized actions performed on behalf of users, defacement, or redirection to malicious sites. Organizations handling sensitive user data or providing critical services via affected websites may face reputational damage, data leakage, and compliance issues under GDPR if user data is compromised. Since the vulnerability requires contributor-level access, insider threats or compromised contributor accounts pose a significant risk. The persistent nature of the XSS means that any visitor to the infected page can be affected, amplifying the potential impact. Attackers could leverage this to target European customers or employees, potentially facilitating broader attacks such as phishing or malware distribution. The lack of known exploits in the wild currently provides a window for proactive mitigation, but the widespread use of WordPress in Europe means many sites could be vulnerable if not promptly addressed.

1. Immediate action should be to update the Biagiotti Core plugin to a version that addresses this vulnerability once released by Mikado Themes. Until then, restrict contributor-level permissions to trusted users only and audit existing contributor accounts for suspicious activity. 2. Implement Web Application Firewall (WAF) rules specifically targeting malicious shortcode attribute patterns to block exploit attempts. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected sites, mitigating the impact of injected scripts. 4. Conduct thorough input validation and output encoding on all shortcode attributes at the application level if custom modifications are possible. 5. Regularly scan WordPress sites for XSS vulnerabilities using specialized security tools and plugins. 6. Educate content contributors about the risks of injecting untrusted content and enforce strict content submission policies. 7. Monitor website traffic and logs for unusual activity indicative of exploitation attempts. 8. Consider temporarily disabling shortcode functionality or the Biagiotti Core plugin if immediate patching is not feasible and risk is high.