CVE-2025-62125 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, found in the Custom Background Changer plugin developed by Anshul Gangrade. This vulnerability affects all versions up to 3.0 and stems from improper neutralization of user-supplied input during the generation of web pages. Specifically, the plugin fails to adequately sanitize or encode input that is later rendered in the web interface, allowing an attacker with at least limited privileges (PR:L) to inject malicious JavaScript code that is stored persistently. The vulnerability requires user interaction (UI:R), meaning that a victim must visit or interact with a compromised page to trigger the malicious script. The CVSS vector indicates network attack vector (AV:N), low attack complexity (AC:L), and a scope change (S:C), meaning the vulnerability can affect components beyond the initially vulnerable module. The impact includes partial loss of confidentiality, integrity, and availability (C:L/I:L/A:L), as the injected scripts can steal session tokens, manipulate page content, or perform actions on behalf of the user. No patches or known exploits are currently available, but the vulnerability is publicly disclosed and should be addressed promptly. The plugin is typically used in web environments to customize background visuals, making it a target for attackers aiming to compromise web application users or administrators. The persistent nature of the XSS increases the risk as malicious payloads remain active until removed or patched.

For European organizations, this vulnerability poses a risk primarily to web applications utilizing the Custom Background Changer plugin. Successful exploitation can lead to session hijacking, unauthorized actions, data theft, and potential spread of malware through injected scripts. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR breaches due to data exposure), and disrupt business operations. Given the scope change in the vulnerability, attackers may leverage it to escalate privileges or compromise additional components within the web infrastructure. Organizations with customer-facing portals, internal dashboards, or content management systems using this plugin are particularly vulnerable. The requirement for user interaction limits mass exploitation but targeted phishing or social engineering campaigns could increase risk. The absence of known exploits currently provides a window for proactive mitigation, but the medium CVSS score indicates a meaningful threat that should not be ignored.

1. Immediately audit all web applications and services to identify usage of the Custom Background Changer plugin, especially versions up to 3.0. 2. Disable or remove the plugin where it is not essential to reduce attack surface. 3. Implement strict input validation and output encoding on all user-supplied data, particularly in areas where the plugin processes or displays content. 4. Employ Content Security Policy (CSP) headers to restrict execution of unauthorized scripts and reduce XSS impact. 5. Monitor web logs and user activity for unusual behavior indicative of XSS exploitation attempts. 6. Educate users and administrators about the risks of interacting with suspicious links or content that could trigger stored XSS. 7. Prepare to deploy patches or updates from the vendor as soon as they become available, and subscribe to vulnerability advisories for timely information. 8. Consider deploying Web Application Firewalls (WAFs) with rules tailored to detect and block XSS payloads related to this plugin. 9. Review and harden authentication and session management controls to limit damage from potential session hijacking.