CVE-2025-7056 is a Medium severity Stored Cross-Site Scripting (XSS) vulnerability identified in the UrlShortener extension of the Wikimedia Foundation's Mediawiki software, specifically affecting versions 1.42.x prior to 1.42.7 and 1.43.x prior to 1.43.2. The vulnerability arises due to improper neutralization of input during web page generation, classified under CWE-79. This flaw allows an attacker to inject malicious scripts that are stored on the server and subsequently executed in the browsers of users who access the affected pages. Since the vulnerability is in the UrlShortener extension, which processes and displays shortened URLs, malicious payloads can be embedded in these URLs or related input fields. The CVSS v3.1 score of 6.3 reflects a scenario where the attack vector is network-based (AV:N), requires no privileges (PR:N), but does require user interaction (UI:R). The impact affects confidentiality, integrity, and availability to a limited extent, as the attacker can execute arbitrary scripts in the context of the victim's browser session, potentially stealing cookies, session tokens, or performing actions on behalf of the user. No known exploits are currently reported in the wild, and no official patches are linked yet, but the vulnerability has been publicly disclosed as of July 7, 2025. The issue is significant because Mediawiki is widely used for collaborative documentation and knowledge bases, including Wikipedia and many enterprise wikis, making the extension's security critical for maintaining trust and data integrity.

For European organizations, the impact of this vulnerability could be substantial, especially for those relying on Mediawiki for internal knowledge management, documentation, or public-facing information portals. Exploitation could lead to session hijacking, unauthorized actions performed by users, or the spread of malware through injected scripts. This could compromise sensitive organizational information, disrupt operations, and damage reputations. Public sector entities, educational institutions, and enterprises using Mediawiki may face increased risk of targeted attacks exploiting this XSS flaw to gain footholds or escalate privileges. Additionally, the vulnerability could be leveraged in phishing campaigns or social engineering attacks by embedding malicious URLs that appear legitimate. Given the collaborative nature of Mediawiki platforms, the risk of widespread impact is elevated if attackers manage to inject persistent scripts that affect multiple users. The lack of known exploits currently reduces immediate risk, but the public disclosure necessitates prompt attention to prevent future exploitation.

European organizations should prioritize upgrading the Mediawiki UrlShortener extension to versions 1.42.7 or 1.43.2 as soon as these patches become available. Until patches are released, organizations should implement strict input validation and output encoding on any user-generated content related to URL shortening features. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. Regularly audit and monitor Mediawiki installations for suspicious activity or unexpected content injections. Disable or restrict the UrlShortener extension if it is not essential to reduce the attack surface. Educate users about the risks of clicking on shortened URLs from untrusted sources and encourage cautious behavior. Additionally, implement web application firewalls (WAFs) with rules tailored to detect and block XSS payloads targeting Mediawiki extensions. Finally, maintain up-to-date backups and incident response plans to quickly recover from any compromise resulting from exploitation of this vulnerability.