CVE-2025-7431 is a Stored Cross-Site Scripting (XSS) vulnerability affecting the ajay Knowledge Base plugin for WordPress, specifically impacting all versions up to and including 2.3.1. The vulnerability arises from improper input sanitization and insufficient output escaping of the plugin slug setting. This flaw allows an authenticated attacker with administrator-level privileges to inject arbitrary malicious scripts into pages generated by the plugin. These scripts execute whenever any user accesses the compromised page, potentially leading to session hijacking, privilege escalation, or other malicious activities. Notably, this vulnerability is limited to WordPress multi-site installations or single-site installations where the unfiltered_html capability is disabled, which restricts the ability to post unfiltered HTML content. The CVSS 3.1 base score is 4.4 (medium severity), reflecting that exploitation requires high privileges (administrator) and high attack complexity, with no user interaction needed. The vulnerability affects confidentiality and integrity but does not impact availability. No known exploits are currently reported in the wild, and no patches or fixes have been linked yet. The vulnerability is classified under CWE-79, which corresponds to improper neutralization of input during web page generation, a common vector for XSS attacks in web applications.

For European organizations using WordPress with the ajay Knowledge Base plugin in multi-site configurations or with unfiltered_html disabled, this vulnerability poses a moderate security risk. An attacker with administrator access could inject malicious scripts that execute in the context of other users' browsers, potentially leading to theft of session cookies, unauthorized actions on behalf of users, or distribution of malware. Although exploitation requires administrator privileges, insider threats or compromised admin accounts could leverage this vulnerability to escalate attacks. The impact on confidentiality and integrity could lead to data breaches or defacement of knowledge base content, undermining trust and compliance with data protection regulations such as GDPR. Since availability is not affected, service disruption is unlikely. However, the multi-site context means that multiple sites managed under a single WordPress installation could be compromised simultaneously, increasing the scope of impact. European organizations relying on this plugin for internal knowledge management or customer-facing documentation should be aware of the risk of persistent XSS attacks that could affect users and administrators alike.

To mitigate this vulnerability, European organizations should first verify if they use the ajay Knowledge Base plugin version 2.3.1 or earlier in multi-site WordPress installations or with unfiltered_html disabled. Immediate steps include restricting administrator access to trusted personnel and enforcing strong authentication mechanisms such as multi-factor authentication to reduce the risk of compromised admin accounts. Administrators should audit plugin settings, especially the plugin slug, for suspicious or unauthorized changes. Since no official patch is currently linked, organizations should consider temporarily disabling the plugin or reverting to a single-site configuration if feasible. Implementing a Web Application Firewall (WAF) with rules to detect and block XSS payloads targeting the plugin slug parameter can provide additional protection. Monitoring logs for unusual administrator activity and scanning for injected scripts in knowledge base pages is recommended. Finally, organizations should stay alert for vendor updates or patches and apply them promptly once available.