CVE-2025-62125 identifies a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79 in the Custom Background Changer plugin developed by Anshul Gangrade, affecting versions up to 3.0. The vulnerability stems from improper neutralization of input during web page generation, allowing malicious actors to inject persistent scripts into web pages served to other users. The CVSS 3.1 base score is 6.5, reflecting a medium severity level, with an attack vector of network (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), and user interaction (UI:R). The scope is changed (S:C), indicating that exploitation can affect resources beyond the initially vulnerable component. The impact metrics indicate low confidentiality, integrity, and availability impacts individually, but combined they pose a meaningful risk. No patches or known exploits are currently available, suggesting the vulnerability is newly disclosed. Stored XSS can be leveraged to execute arbitrary JavaScript in victims’ browsers, potentially leading to session hijacking, credential theft, or unauthorized actions within the context of the vulnerable application. The requirement for privileges and user interaction limits exploitation to some extent but does not eliminate risk, especially in environments where multiple users have access to the plugin’s interface or where attackers can trick users into interacting with malicious content. The vulnerability affects web applications using the Custom Background Changer plugin, which is typically employed to customize UI backgrounds, indicating a web-facing attack surface. The persistent nature of the XSS increases the potential impact compared to reflected variants.

For European organizations, this vulnerability poses risks primarily to web applications or intranet portals utilizing the Custom Background Changer plugin. Exploitation could lead to unauthorized script execution in users’ browsers, resulting in session hijacking, data leakage, or unauthorized actions performed with the victim’s privileges. This can compromise user confidentiality and integrity of data, and potentially availability if malicious scripts disrupt normal operations. Organizations with sensitive user data or critical web services are at higher risk. The requirement for user interaction and privileges reduces the likelihood of widespread automated exploitation but does not preclude targeted attacks, especially in environments with multiple users or where attackers can socially engineer victims. The absence of patches increases exposure time, and the lack of known exploits suggests an opportunity for proactive mitigation. The impact is more significant for sectors relying heavily on web-based collaboration tools or customer-facing portals, including finance, healthcare, and government services in Europe.

1. Immediately audit and restrict access to the Custom Background Changer plugin, limiting usage to trusted administrators only. 2. Implement strict input validation and output encoding on all user-supplied data processed by the plugin to neutralize malicious scripts. 3. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers. 4. Monitor web application logs and user activity for signs of unusual behavior or injection attempts. 5. Educate users about the risks of interacting with suspicious links or content that could trigger the stored XSS. 6. If possible, disable or remove the plugin until an official patch is released. 7. Engage with the vendor or community to track patch availability and apply updates promptly. 8. Conduct regular security assessments and penetration testing focusing on web application input handling. 9. Use web application firewalls (WAFs) configured to detect and block XSS payloads targeting this plugin. 10. Maintain an incident response plan to quickly address any exploitation attempts.