CVE-2025-62702 is a stored Cross-site Scripting (XSS) vulnerability classified under CWE-79, found in the PageTriage Extension of the Mediawiki platform maintained by the Wikimedia Foundation. This vulnerability occurs due to improper neutralization of user-supplied input during the generation of web pages, allowing malicious scripts to be injected and stored persistently within the application. The affected versions include the master branch prior to version 1.44. The vulnerability's CVSS 4.0 base score is 6.9, indicating a medium severity level. The vector details specify that the attack can be performed remotely over the network (AV:N) without any authentication (PR:N) or user interaction (UI:N), making it relatively easy to exploit. The impact on confidentiality, integrity, and availability is limited but present, as the injected scripts can execute in the context of other users, potentially leading to session hijacking, credential theft, or unauthorized actions. The vulnerability affects the PageTriage Extension, which is used to assist in reviewing and managing new pages on Mediawiki sites, including Wikimedia projects. Although no known exploits are currently reported in the wild, the presence of this vulnerability in a widely used open-source platform poses a risk to organizations relying on Mediawiki for content management and collaboration. The issue was reserved and published in October 2025, and no official patches or fixes have been linked yet, emphasizing the need for proactive mitigation.

For European organizations, the impact of CVE-2025-62702 can be significant, especially for those relying on Mediawiki installations for internal knowledge bases, documentation, or public-facing wikis. Exploitation of this stored XSS vulnerability could allow attackers to execute arbitrary JavaScript in the browsers of users accessing the affected pages, leading to session hijacking, theft of sensitive information, or unauthorized actions performed on behalf of legitimate users. This could compromise the confidentiality and integrity of organizational data and potentially disrupt operations if critical information is altered or deleted. Public institutions, educational organizations, and companies with collaborative platforms based on Mediawiki are at risk of reputational damage and compliance issues under GDPR if personal data is exposed or manipulated. The vulnerability's ease of exploitation without authentication increases the threat level, as attackers do not require credentials or user interaction to launch attacks. However, the limited scope of impact and lack of direct availability disruption moderate the overall risk. Organizations in Europe with extensive Mediawiki deployments should be vigilant, as attackers might target these platforms to gain footholds or pivot to other internal systems.

To mitigate CVE-2025-62702 effectively, European organizations should take several specific actions beyond generic XSS prevention. First, monitor the Wikimedia Foundation's official repositories and security advisories for patches or updates to the PageTriage Extension and apply them promptly once available. In the interim, consider disabling or restricting access to the PageTriage Extension if feasible, especially on public-facing instances. Implement strict input validation and output encoding on all user-supplied data within Mediawiki, focusing on the PageTriage Extension's input fields to prevent malicious script injection. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts in browsers accessing the wiki. Conduct regular security audits and penetration testing targeting the Mediawiki environment to detect any residual XSS or related vulnerabilities. Educate users and administrators about the risks of XSS and encourage reporting of suspicious behavior. Additionally, monitor web server and application logs for unusual requests or error patterns that might indicate exploitation attempts. For organizations with sensitive data, consider isolating Mediawiki instances from critical internal networks to limit potential lateral movement in case of compromise.