CVE-2025-59525: Horilla HRMS XSS Vulnerability

CVE-2025-59525 Overview

CVE-2025-59525 is a stored Cross-Site Scripting (XSS) vulnerability in Horilla, a free and open source Human Resource Management System (HRMS). The flaw affects all versions prior to 1.4.0 and stems from improper sanitization of uploaded content across the application. Attackers can upload malicious Scalable Vector Graphics (SVG) files or abuse the allowed <embed> tag to inject JavaScript. The payload executes when other users, including administrators, view impacted content such as announcements. Successful exploitation can lead to session theft and full administrator account takeover, compromising sensitive HR data. The issue is tracked under [CWE-79] and was patched in Horilla version 1.4.0.

Critical Impact
Attackers can achieve administrator account takeover in Horilla HRMS by uploading weaponized SVG files that execute JavaScript in the browser of any user viewing the affected content.

Affected Products

Horilla HRMS versions prior to 1.4.0
Deployments serving user-uploaded SVG or <embed> content without sanitization
Instances rendering announcements or similar shared content to administrators

Discovery Timeline

2025-09-24 - CVE-2025-59525 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-59525

Vulnerability Analysis

Horilla accepts SVG file uploads and renders them to users without stripping active content. SVG is an XML-based image format that permits inline <script> elements and event handlers such as onload. When a browser renders such an SVG inline, embedded JavaScript executes in the origin of the Horilla application. The vulnerability is compounded by permissive handling of the <embed> HTML tag, which can load attacker-controlled resources. Because the payload persists server-side and executes on view, this is a stored XSS with a broad blast radius. An attacker with the ability to upload files or post announcements can target higher-privileged reviewers.

Root Cause

The root cause is missing output sanitization and inadequate MIME/content-type validation for uploaded artifacts. Horilla did not strip scriptable elements from SVG uploads and permitted <embed> in rendered content. This maps to [CWE-79]: Improper Neutralization of Input During Web Page Generation.

Attack Vector

Exploitation requires network access to the Horilla application and the ability to submit content that another user will render. In many deployments, self-service HR features grant employees upload capabilities, lowering the barrier to attack. Once an administrator opens the crafted announcement or profile view, the injected JavaScript runs with the admin's session context, enabling cookie theft, CSRF-style privileged actions, or credential harvesting.

No verified proof-of-concept code is publicly available in the referenced sources. Refer to the GitHub Security Advisory GHSA-rp5m-vpqr-vpvp for technical details.

Detection Methods for CVE-2025-59525

Indicators of Compromise

SVG files in Horilla upload directories containing <script> tags, javascript: URIs, or on* event handler attributes
HTML content in announcements or profile fields containing <embed> elements referencing external or data URIs
Unusual administrator session activity shortly after viewing user-generated announcements or attachments

Detection Strategies

Scan the Horilla media and upload directories for SVG payloads matching regex patterns such as <script, onload=, or xlink:href="javascript:
Review web server access logs for GET requests to .svg assets immediately preceding privileged API calls from the same session
Enable Content Security Policy (CSP) violation reporting to surface inline script execution attempts from rendered SVG content

Monitoring Recommendations

Alert on administrator account changes, permission grants, or password resets that follow SVG or announcement views
Monitor for outbound HTTP requests from browsers viewing Horilla pages to unexpected external hosts, indicating exfiltration
Track file upload endpoints for anomalously sized or MIME-mismatched SVG submissions from low-privilege accounts

How to Mitigate CVE-2025-59525

Immediate Actions Required

Upgrade Horilla to version 1.4.0 or later, which contains the official fix for this vulnerability
Audit existing SVG uploads and announcement content for embedded <script> tags or <embed> elements and remove malicious artifacts
Rotate administrator credentials and invalidate active sessions if evidence of exploitation is found

Patch Information

Horilla version 1.4.0 remediates CVE-2025-59525 by implementing proper sanitization for uploaded SVG files and restricting the <embed> tag. Release details are available at the Horilla 1.4.0 release notes and the GitHub Security Advisory GHSA-rp5m-vpqr-vpvp.

Workarounds

Restrict file upload permissions to trusted roles until the upgrade is deployed
Serve uploaded SVG files with the Content-Type: image/svg+xml header combined with Content-Disposition: attachment to prevent inline rendering
Deploy a strict Content Security Policy (CSP) that disallows inline scripts and restricts object-src and embed sources
Place Horilla behind a web application firewall (WAF) with rules to block SVG payloads containing scriptable elements

bash

# Example nginx configuration to force SVG downloads and enforce CSP
location ~* \.svg$ {
    add_header Content-Disposition "attachment";
    add_header X-Content-Type-Options "nosniff";
}

add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; base-uri 'self';";