CVE-2025-11265 is a stored Cross-Site Scripting (XSS) vulnerability identified in the VK All in One Expansion Unit plugin for WordPress, a popular plugin used to enhance website functionality. The vulnerability exists in all versions up to and including 9.112.1 and stems from a logic error in the plugin's call-to-action (CTA) save function. Specifically, the sanitization callbacks intended to neutralize potentially malicious script-related HTML tags are read from an incorrect variable ($custom_field_name) instead of the correct one ($custom_field_options). This error causes the sanitization process to be completely bypassed for the 'vkExUnit_cta_url' and 'vkExUnit_cta_button_text' parameters. As a result, authenticated users with Contributor-level access or higher can inject arbitrary JavaScript code into pages. When other users visit these pages, the injected scripts execute in their browsers, potentially leading to session hijacking, unauthorized actions, or phishing attacks. The vulnerability has a CVSS 3.1 base score of 6.4, reflecting medium severity, with an attack vector over the network, low complexity, requiring privileges but no user interaction, and impacting confidentiality and integrity with a scope change. No patches or fixes have been released yet, and no known exploits are currently in the wild. The flaw is categorized under CWE-80, indicating improper neutralization of script-related HTML tags in web pages, a common XSS weakness. This vulnerability highlights the importance of correct input validation and sanitization in web applications, especially in widely used CMS plugins.

For European organizations, this vulnerability poses a moderate risk primarily to websites running WordPress with the VK All in One Expansion Unit plugin installed. Exploitation could allow attackers with contributor-level access to inject malicious scripts that execute in the browsers of site visitors or administrators. This can lead to session hijacking, theft of sensitive information, defacement, or redirection to malicious sites, undermining user trust and potentially causing reputational damage. Since the attack requires authenticated access, insider threats or compromised contributor accounts are the main vectors. The impact is particularly significant for organizations relying on WordPress for customer-facing portals, e-commerce, or internal collaboration sites. Given the widespread use of WordPress across Europe, especially in Germany, the UK, France, and the Netherlands, the potential attack surface is substantial. Additionally, sectors such as government, education, and SMEs that often use WordPress plugins extensively may face increased exposure. The lack of a patch at the time of disclosure increases the window of vulnerability, emphasizing the need for immediate mitigation measures.

1. Immediately audit user roles and permissions on WordPress sites to ensure that only trusted users have Contributor-level or higher access. 2. Implement strict access controls and multi-factor authentication (MFA) for all authenticated users to reduce the risk of account compromise. 3. Monitor and review content submitted via the 'vkExUnit_cta_url' and 'vkExUnit_cta_button_text' fields for suspicious or unexpected script content. 4. Employ Web Application Firewalls (WAFs) with custom rules to detect and block typical XSS payloads targeting these parameters. 5. Disable or restrict the use of the VK All in One Expansion Unit plugin temporarily if feasible until an official patch is released. 6. Keep WordPress core and all plugins updated and subscribe to vendor security advisories for timely patch deployment. 7. Educate content contributors about safe input practices and the risks of injecting untrusted content. 8. Use Content Security Policy (CSP) headers to limit the execution of inline scripts and reduce the impact of potential XSS attacks. 9. Conduct regular security scans and penetration tests focusing on plugin vulnerabilities and input sanitization. 10. Prepare incident response plans to quickly address any exploitation attempts or detected compromises.