CVE-2025-62664 is a stored Cross-site Scripting (XSS) vulnerability classified under CWE-79 that affects the ImageRating extension of Mediawiki, an open-source wiki platform widely used for collaborative content management. The vulnerability is due to improper neutralization of input during web page generation, meaning that user-supplied data is not correctly sanitized or encoded before being embedded into web pages. This flaw allows an attacker to inject malicious JavaScript code that is stored persistently within the wiki content. When other users access the affected pages, the malicious scripts execute in their browsers, potentially leading to session hijacking, credential theft, or unauthorized actions performed with the victim's privileges. The vulnerability affects the master branch of the ImageRating extension before version 1.39. The CVSS 4.0 score of 6.9 indicates a medium severity level, with an attack vector over the network, low attack complexity, no privileges or user interaction required, and limited impact on confidentiality, integrity, and availability. No public exploits have been reported so far, but the risk remains significant due to the stored nature of the XSS, which can affect all users accessing compromised content. The Wikimedia Foundation has published the vulnerability details, but no patch links are currently available, suggesting that remediation is pending or in progress. Organizations using Mediawiki with the ImageRating extension should be aware of this vulnerability, especially if their wikis are publicly accessible or used by many users, as the impact can extend beyond simple defacement to more severe security breaches.

For European organizations, the impact of CVE-2025-62664 can be substantial, particularly for those relying on Mediawiki for knowledge management, documentation, or collaborative projects. Stored XSS vulnerabilities can lead to session hijacking, allowing attackers to impersonate legitimate users and gain unauthorized access to sensitive information or administrative functions. This can compromise confidentiality and integrity of organizational data. Additionally, attackers may use the vulnerability to deliver phishing payloads or malware, damaging organizational reputation and user trust. Public sector entities, educational institutions, and cultural organizations that use Mediawiki extensively are at higher risk, as their wikis often contain sensitive or authoritative content. The vulnerability could also be exploited to deface content, disrupt operations, or spread misinformation. Given the network-based attack vector and lack of required privileges or user interaction, exploitation can be automated and widespread if not mitigated promptly. Although the availability impact is limited, the overall risk to data security and user trust is significant.

To mitigate CVE-2025-62664, European organizations should: 1) Monitor official Wikimedia Foundation channels for patches or updates to the ImageRating extension and apply them immediately once available. 2) If patches are not yet released, consider disabling or removing the ImageRating extension temporarily to eliminate the attack surface. 3) Implement strict input validation and output encoding on all user-generated content within the wiki, ensuring that scripts and HTML tags are properly sanitized. 4) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers accessing the wiki. 5) Conduct regular security audits and penetration testing focused on XSS vulnerabilities in Mediawiki deployments. 6) Educate wiki administrators and users about the risks of XSS and encourage vigilance for suspicious content or behavior. 7) Use web application firewalls (WAFs) with rules tailored to detect and block XSS payloads targeting Mediawiki. 8) Monitor logs and user reports for signs of exploitation attempts or unusual activity. These measures go beyond generic advice by focusing on immediate risk reduction, proactive detection, and layered defenses specific to the Mediawiki environment.