CVE-2025-46518 is a Stored Cross-site Scripting (XSS) vulnerability classified under CWE-79, affecting the phpaddicted plugin 'IGIT Related Posts With Thumb Image After Posts' up to version 4.5.3. This vulnerability arises due to improper neutralization of user input during web page generation, allowing malicious scripts to be injected and stored within the plugin's output. When a victim accesses a page containing the injected payload, the malicious script executes in their browser context. The CVSS 3.1 base score of 6.5 reflects a medium severity level, with an attack vector of network (remote exploitation), low attack complexity, requiring privileges (PR:L) and user interaction (UI:R). The scope is changed (S:C), indicating that exploitation can affect components beyond the vulnerable plugin itself. The impact includes limited confidentiality, integrity, and availability loss, as the attacker can execute arbitrary scripts in users' browsers, potentially stealing session cookies, performing actions on behalf of users, or defacing content. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability is significant because stored XSS can lead to persistent attacks affecting multiple users, especially in environments where the plugin is widely used to display related posts with thumbnails after blog posts or articles. The vulnerability requires an attacker to have at least some level of privilege to inject the malicious input and for users to interact with the affected pages to trigger the payload.

For European organizations, this vulnerability poses a risk primarily to websites using the phpaddicted IGIT Related Posts With Thumb Image After Posts plugin, commonly found in WordPress environments. Exploitation could lead to session hijacking, unauthorized actions performed on behalf of users, defacement, or distribution of malware through injected scripts. This can damage organizational reputation, lead to data breaches involving user information, and potentially violate GDPR requirements concerning data protection and breach notification. The medium severity suggests that while the impact is not catastrophic, it is significant enough to warrant prompt attention, especially for organizations with high web traffic or sensitive user data. The requirement for some privilege and user interaction limits the attack surface but does not eliminate risk, particularly in environments with multiple contributors or less stringent input validation controls. Additionally, the scope change indicates that the vulnerability could affect other components or plugins, potentially amplifying the impact if chained with other vulnerabilities.

Organizations should immediately audit their WordPress installations to identify the presence of the IGIT Related Posts With Thumb Image After Posts plugin and verify the version in use. Until an official patch is released, administrators should consider disabling or removing the plugin to eliminate the attack vector. Implementing Web Application Firewall (WAF) rules that detect and block typical XSS payloads targeting the plugin's output can provide temporary protection. Additionally, enforcing strict Content Security Policy (CSP) headers can mitigate the impact of injected scripts by restricting script execution sources. Review and tighten user input validation and sanitization processes, especially for users with privileges to add or edit content that the plugin processes. Monitoring web logs for unusual input patterns or user behavior can help detect attempted exploitation. Once a patch is available, prioritize its deployment and verify the effectiveness through security testing. Educating content contributors about the risks of injecting untrusted content and enforcing the principle of least privilege for user roles can further reduce exploitation likelihood.