CVE-2026-1147: Queue Management System XSS Vulnerability

CVE-2026-1147 Overview

A Cross-Site Scripting (XSS) vulnerability has been identified in the SourceCodester/Patrick Mvuma Patients Waiting Area Queue Management System version 1.0. This vulnerability affects the /php/api_patient_schedule.php file, where improper handling of the Reason parameter allows attackers to inject malicious scripts. The attack can be initiated remotely and the exploit has been publicly disclosed.

Critical Impact

Attackers can inject malicious scripts through the Reason parameter in the patient scheduling API, potentially enabling session hijacking, data theft, or unauthorized actions within the healthcare queue management system.

Affected Products

• SourceCodester/Patrick Mvuma Patients Waiting Area Queue Management System 1.0
• /php/api_patient_schedule.php endpoint

Discovery Timeline

• 2026-01-19 - CVE-2026-1147 published to NVD
• 2026-01-19 - Last updated in NVD database

Technical Details for CVE-2026-1147

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Cross-Site Scripting), where user-supplied input is not properly sanitized before being rendered in the application's response. In the context of a healthcare queue management system, this poses significant risks as attackers could potentially access patient information or manipulate queue operations.

The vulnerable endpoint /php/api_patient_schedule.php accepts a Reason parameter that is processed without adequate input validation or output encoding. When malicious JavaScript code is submitted through this parameter, it is reflected back to users or stored in the database, executing in the context of their browser session.

Healthcare applications are particularly sensitive targets for XSS attacks due to the potential exposure of protected health information (PHI) and the critical nature of patient care workflows.

Root Cause

The root cause of this vulnerability is insufficient input validation and output encoding in the api_patient_schedule.php file. The Reason argument is accepted and processed without proper sanitization, allowing HTML and JavaScript code to be injected and executed in the user's browser context. This represents a failure to implement secure coding practices for handling user-controllable input.

Attack Vector

The attack vector is network-based, meaning an authenticated attacker can remotely exploit this vulnerability. The attack requires low privileges and some user interaction to execute. An attacker would craft a malicious request containing JavaScript code in the Reason parameter of the patient scheduling API. When this data is subsequently displayed to other users or administrators, the injected script executes in their browser session.

The vulnerability can be exploited by submitting specially crafted input containing script tags or JavaScript event handlers to the patient scheduling endpoint. Since the exploit has been publicly disclosed, organizations using this software should consider themselves at elevated risk.

Detection Methods for CVE-2026-1147

Indicators of Compromise

• Unusual JavaScript patterns in log entries for /php/api_patient_schedule.php
• Suspicious HTML tags or script elements appearing in the Reason field of patient schedule records
• Unexpected outbound network requests from user browsers accessing the queue management system
• Session anomalies or unauthorized administrative actions following normal user access

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS payloads in POST/GET parameters
• Monitor application logs for requests to api_patient_schedule.php containing encoded script tags or event handlers
• Deploy content security policy (CSP) headers to detect and report script injection attempts
• Conduct regular vulnerability scanning of the queue management application

Monitoring Recommendations

• Enable detailed logging for all API endpoints, particularly api_patient_schedule.php
• Configure alerts for requests containing common XSS patterns such as <script>, javascript:, or event handler attributes
• Monitor for unusual database entries in patient schedule tables containing HTML or JavaScript code
• Implement real-time browser-side monitoring through CSP violation reporting

How to Mitigate CVE-2026-1147

Immediate Actions Required

• Review and restrict access to the /php/api_patient_schedule.php endpoint to trusted users only
• Implement input validation on all user-supplied parameters, particularly the Reason field
• Apply output encoding for all data rendered in HTML contexts
• Deploy a Web Application Firewall with XSS protection rules enabled

Patch Information

No official vendor patch information is currently available for this vulnerability. Organizations should contact SourceCodester for official remediation guidance. In the meantime, implement the workarounds described below to reduce exposure.

For additional technical details, see VulDB Advisory #341740.

Workarounds

• Implement server-side input validation to strip or reject HTML tags and JavaScript from the Reason parameter
• Apply HTML entity encoding to all user-supplied data before rendering in web pages
• Deploy Content Security Policy (CSP) headers to prevent inline script execution
• Consider disabling or restricting access to the vulnerable API endpoint until a patch is available

# Example Apache configuration to add security headers
<IfModule mod_headers.c>
    # Content Security Policy to prevent inline scripts
    Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'"
    
    # Additional security headers
    Header set X-Content-Type-Options "nosniff"
    Header set X-XSS-Protection "1; mode=block"
</IfModule>