CVE-2025-59525 is a cross-site scripting (XSS) vulnerability identified in horilla, a free and open-source Human Resource Management System (HRMS). The flaw exists in versions prior to 1.4.0 due to improper sanitization of user-supplied inputs during web page generation, specifically involving uploaded SVG files and allowed <embed> HTML elements. SVG files can contain embedded JavaScript, and without proper sanitization, these scripts execute in the context of the victim's browser when viewing affected content such as announcements or other HR-related pages. This vulnerability does not require authentication or user interaction, making it remotely exploitable by attackers who can upload malicious SVG files. The XSS can be chained to perform administrative account takeover by stealing session tokens or executing privileged actions on behalf of the admin user. The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation) and CWE-434 (Unrestricted Upload of File with Dangerous Type). The CVSS 4.0 score of 7.7 reflects high severity due to network exploitability, no required privileges or user interaction, and a high impact on system integrity and confidentiality. The issue was publicly disclosed on September 24, 2025, and patched in horilla version 1.4.0. No known exploits in the wild have been reported yet, but the potential for damage is significant given the sensitive nature of HRMS data and administrative control.

For European organizations, the impact of this vulnerability is substantial. HRMS platforms like horilla manage sensitive employee data including personal identification, payroll, and organizational roles. Exploitation could lead to unauthorized access to confidential employee information, manipulation of HR records, and full administrative account takeover. This compromises data confidentiality, integrity, and availability, potentially leading to regulatory non-compliance under GDPR and other data protection laws. The ability to execute arbitrary JavaScript in an admin context could also facilitate lateral movement within the network or deployment of further malware. Public sector organizations and large enterprises with extensive HR operations are particularly at risk, as compromise could disrupt critical human resource functions and damage organizational reputation.

Immediate mitigation requires upgrading all horilla instances to version 1.4.0 or later, where the vulnerability is patched. Until upgrades are completed, organizations should disable or restrict SVG file uploads and the use of <embed> elements in user-generated content. Implement strict content security policies (CSP) to limit script execution sources and reduce XSS impact. Conduct thorough input validation and sanitization on all file uploads and embedded content. Monitor logs for suspicious upload activity and anomalous access patterns. Educate HR and IT staff about the risks of malicious file uploads and ensure regular backups of HRMS data to enable recovery. Consider deploying web application firewalls (WAFs) with rules targeting XSS payloads in SVG files. Finally, perform security audits and penetration testing focused on file upload and content rendering functionalities.