CVE-2025-52132 is a medium-severity Cross-site Scripting (XSS) vulnerability affecting the Mocca Calendar application, a component of the xwiki-contrib project. This vulnerability exists in versions prior to 2.15 of Mocca Calendar. The flaw arises from improper neutralization of user-supplied input in the 'title' field when rendering the view event page. Specifically, the application fails to adequately sanitize or encode the title parameter, allowing an attacker to inject malicious scripts that execute in the context of the victim's browser. The CVSS 3.1 base score is 6.4, reflecting a network attack vector with low attack complexity, requiring low privileges but no user interaction. The scope is changed, indicating that exploitation can affect resources beyond the vulnerable component. The impact affects confidentiality and integrity but not availability. No known exploits are currently reported in the wild, and no official patches have been linked yet. However, given the nature of XSS, successful exploitation could allow attackers to steal session tokens, perform actions on behalf of users, or deliver further malware payloads within the context of the vulnerable web application. The vulnerability is classified under CWE-79, which is a common and well-understood web application security issue related to improper input validation and output encoding during web page generation.

For European organizations using XWiki with the Mocca Calendar extension, this vulnerability poses a tangible risk to the confidentiality and integrity of user sessions and data. Since XWiki is often deployed in enterprise and collaborative environments for knowledge management, exploitation could lead to unauthorized access to sensitive internal information or manipulation of calendar events. This could disrupt business operations, leak confidential scheduling data, or facilitate further attacks such as phishing or lateral movement within the network. The lack of required user interaction lowers the barrier for exploitation, especially in environments where users have elevated privileges or access to sensitive data. While availability is not directly impacted, the reputational damage and potential regulatory consequences under GDPR for data breaches involving personal information could be significant. The vulnerability's network attack vector means it can be exploited remotely, increasing the threat surface for organizations with externally accessible XWiki instances.

European organizations should prioritize upgrading the Mocca Calendar application to version 2.15 or later once available, as this will contain the necessary fixes to properly sanitize the 'title' input. Until an official patch is released, organizations should implement strict input validation and output encoding at the application or web server level to neutralize potentially malicious scripts in event titles. Employing Web Application Firewalls (WAFs) with custom rules to detect and block suspicious script payloads targeting the calendar's event pages can provide interim protection. Additionally, organizations should audit user privileges to minimize the number of users who can create or edit calendar events, reducing the risk of malicious input. Security teams should monitor logs for unusual activity related to calendar event creation or viewing and educate users about the risks of unsolicited links or content within the XWiki environment. Finally, applying Content Security Policy (CSP) headers can help mitigate the impact of XSS by restricting the execution of unauthorized scripts.