CVE-2025-58064 is a Cross-Site Scripting (XSS) vulnerability identified in CKEditor 5, a widely used modern JavaScript rich-text editor with an MVC architecture. The vulnerability affects versions 44.2.0 through 45.2.1 and 46.0.0 through 46.0.2 of both ckeditor5 and ckeditor5-clipboard. The root cause is improper neutralization of input during web page generation, specifically when certain editor configurations are enabled. Exploitation requires that either the HTML embed plugin is enabled or a custom plugin introduces an editable element with the view RawElement enabled. Under these conditions, an attacker who can insert malicious content into the editor can trigger unauthorized JavaScript code execution when a specific user action occurs. This could lead to client-side script execution in the context of the vulnerable web application. The vulnerability does not require authentication but does require user interaction to trigger the payload. The issue has been addressed in versions 45.2.2 and 46.0.3 of ckeditor5 and ckeditor5-clipboard. The CVSS v4.0 score is 2.3 (low severity), reflecting the limited impact and exploitation complexity. No known exploits are currently reported in the wild. The vulnerability is classified under CWE-79, which covers improper neutralization of input leading to XSS attacks.

For European organizations, the impact of this vulnerability depends on the extent to which CKEditor 5 is integrated into their web applications, particularly those that enable the HTML embed plugin or use custom plugins with RawElement editing. Successful exploitation could allow attackers to execute arbitrary JavaScript in the context of the affected web application, potentially leading to session hijacking, defacement, or redirection to malicious sites. While the vulnerability is rated low severity, it can still undermine user trust and lead to data exposure or manipulation if exploited in sensitive environments such as financial services, healthcare, or government portals. The requirement for user interaction and specific editor configurations limits widespread exploitation, but targeted attacks against high-value European organizations remain a concern. Additionally, organizations subject to strict data protection regulations like GDPR must consider the reputational and compliance risks associated with XSS vulnerabilities.

European organizations should promptly update CKEditor 5 and ckeditor5-clipboard to versions 45.2.2 or 46.0.3 or later to remediate this vulnerability. Beyond patching, organizations should review their CKEditor configurations to disable the HTML embed plugin if not required and audit any custom plugins that introduce editable elements with RawElement enabled. Implementing Content Security Policy (CSP) headers can help mitigate the impact of potential XSS by restricting the execution of unauthorized scripts. Additionally, input validation and output encoding should be enforced at the application level to prevent injection of malicious content into the editor. Regular security code reviews and penetration testing focusing on rich-text editor components are recommended to detect similar issues. Monitoring user activity and logs for suspicious behavior related to editor usage can provide early detection of exploitation attempts.