CVE-2025-7056 is a stored Cross-site Scripting (XSS) vulnerability identified in the UrlShortener Extension of the Wikimedia Foundation's Mediawiki software. This vulnerability arises due to improper neutralization of input during web page generation, classified under CWE-79. Specifically, versions 1.42.x before 1.42.7 and 1.43.x before 1.43.2 of the UrlShortener Extension are affected. Stored XSS occurs when malicious scripts injected by an attacker are permanently stored on the target server (e.g., in a database) and subsequently served to users without proper sanitization or encoding. In this case, the UrlShortener Extension fails to properly sanitize user-supplied input that is embedded in web pages, allowing attackers to inject arbitrary JavaScript code. When other users access the affected pages, the malicious script executes in their browsers within the security context of the Mediawiki site. This can lead to session hijacking, credential theft, unauthorized actions on behalf of the user, or distribution of malware. The vulnerability does not currently have a CVSS score, and no known exploits have been reported in the wild as of the publication date. However, given the nature of stored XSS and the widespread use of Mediawiki in various organizations, the risk remains significant until patched. The Wikimedia Foundation has published the vulnerability but has not yet linked to specific patches, indicating that fixes may be forthcoming or recently released.

For European organizations using Mediawiki with the UrlShortener Extension, this vulnerability poses a risk to confidentiality, integrity, and availability of information. Attackers exploiting this stored XSS could hijack user sessions, leading to unauthorized access to sensitive internal wiki content, potentially exposing confidential organizational knowledge or intellectual property. Integrity could be compromised if attackers inject malicious content or manipulate wiki pages, misleading users or damaging organizational reputation. Availability could be indirectly affected if attackers use the vulnerability to conduct phishing or malware distribution campaigns targeting users. Since Mediawiki is widely used in government, educational, and corporate environments across Europe for knowledge management and collaboration, exploitation could disrupt critical workflows. The lack of known exploits in the wild suggests limited immediate risk, but the vulnerability's presence in commonly deployed versions means European organizations should act promptly to prevent future attacks. Additionally, attackers could leverage this vulnerability as part of multi-stage attacks targeting European entities, especially those with high-value information assets.

European organizations should immediately audit their Mediawiki installations to determine if the UrlShortener Extension versions 1.42.x prior to 1.42.7 or 1.43.x prior to 1.43.2 are in use. If so, they should prioritize upgrading to the fixed versions as soon as they become available from the Wikimedia Foundation. Until patches are applied, organizations can implement temporary mitigations such as disabling the UrlShortener Extension if feasible, or restricting access to the wiki to trusted users only. Web Application Firewalls (WAFs) with custom rules to detect and block suspicious input patterns related to URL shortening parameters can reduce exploitation risk. Additionally, organizations should enforce Content Security Policy (CSP) headers to limit the impact of injected scripts and conduct user awareness training to recognize phishing attempts that might leverage this vulnerability. Regular security scanning and penetration testing focused on XSS vectors in Mediawiki deployments can help identify residual risks. Finally, monitoring logs for unusual activity related to the UrlShortener Extension can provide early detection of exploitation attempts.