CVE-2025-13902: Cross-Site Scripting (XSS) Vulnerability

CVE-2025-13902 Overview

CVE-2025-13902 is a Cross-Site Scripting (XSS) vulnerability (CWE-79) that affects Schneider Electric web server components. The vulnerability exists due to improper neutralization of user input during web page generation, allowing authenticated attackers to inject malicious JavaScript code that executes when a victim hovers over a crafted element on the affected web server.

Critical Impact
Authenticated attackers can execute arbitrary JavaScript in victims' browsers through malicious hover events, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of the victim.

Affected Products

Schneider Electric web server components (specific product versions detailed in vendor advisory)

Discovery Timeline

2026-03-10 - CVE-2025-13902 published to NVD
2026-03-11 - Last updated in NVD database

Technical Details for CVE-2025-13902

Vulnerability Analysis

This stored XSS vulnerability allows authenticated attackers to inject malicious JavaScript payloads into web pages served by the affected Schneider Electric product. The vulnerability is triggered through user interaction—specifically when a victim hovers their mouse pointer over a maliciously crafted HTML element that contains the injected payload.

The attack requires low privileges (authentication) and passive user interaction, but can impact the confidentiality and integrity of downstream systems through the victim's browser context. The vulnerability affects the web interface's input handling mechanisms, where user-supplied data is rendered without proper sanitization or encoding.

Root Cause

The root cause is improper neutralization of input during web page generation. The affected web application fails to adequately sanitize or encode user-controlled input before incorporating it into dynamically generated HTML content. This allows attackers to inject executable script content that persists on the server and executes in the browsers of users who interact with the malicious elements.

Attack Vector

The attack is network-based and requires the attacker to have authenticated access to the vulnerable web application. The attacker injects a malicious payload containing JavaScript code into a field or parameter that is later rendered on a web page. When another authenticated user views the page and hovers over the crafted element, the injected JavaScript executes within that user's browser session.

The hover-based trigger mechanism (likely using HTML event attributes such as onmouseover) allows the attack to remain stealthy until user interaction occurs. Once triggered, the malicious script can access session cookies, perform actions as the victim user, redirect to phishing pages, or exfiltrate sensitive information.

Detection Methods for CVE-2025-13902

Indicators of Compromise

Unexpected HTML event handler attributes (onmouseover, onmouseenter, onfocus) containing JavaScript in web application data fields
User-submitted content containing encoded or obfuscated script tags or event handlers
Anomalous outbound network connections from user browsers to external domains after interacting with the web interface
Reports of unexpected behavior or redirects when hovering over elements in the affected web application

Detection Strategies

Deploy Web Application Firewalls (WAF) with XSS detection rules to identify and block malicious payloads in HTTP requests
Implement Content Security Policy (CSP) headers to prevent inline script execution and report violations
Monitor web server logs for requests containing suspicious patterns such as <script>, event handlers, or JavaScript protocol URLs
Conduct regular security scanning of the web application for stored XSS vulnerabilities

Monitoring Recommendations

Enable CSP violation reporting and monitor for blocked inline script execution attempts
Review application audit logs for unusual data submissions by authenticated users
Set up alerts for DOM manipulation or script injection patterns in web application monitoring tools
Monitor endpoint detection and response (EDR) solutions for browser-based attacks originating from the affected web interface

How to Mitigate CVE-2025-13902

Immediate Actions Required

Review the Schneider Electric Security Notice for specific remediation guidance
Apply vendor-provided patches or updates as soon as they become available
Implement strict input validation and output encoding for all user-supplied data
Restrict access to the affected web interface to trusted users only until patches are applied

Patch Information

Schneider Electric has published a security notice (SEVD-2026-069-02) addressing this vulnerability. Organizations should review the Schneider Electric Security Notice for detailed patch information, affected product versions, and specific remediation steps.

Workarounds

Implement Content Security Policy (CSP) headers with strict directives to prevent inline script execution: Content-Security-Policy: default-src 'self'; script-src 'self'
Deploy a Web Application Firewall (WAF) with XSS filtering rules in front of the affected web server
Limit authenticated user access to the affected web interface through network segmentation
Educate users about the risks of interacting with suspicious content and implement browser-based XSS protections where available
Monitor user activity logs for signs of malicious payload injection and investigate anomalies promptly