CVE-2026-7089: Home Service System 1.0 XSS Vulnerability

CVE-2026-7089 Overview

A stored Cross-Site Scripting (XSS) vulnerability has been identified in code-projects Home Service System 1.0. The vulnerability exists in the /booking.php file within the Appointment Booking component. Attackers can inject malicious scripts through the fname and lname parameters, which are not properly sanitized before being stored and rendered. The exploit has been publicly disclosed, enabling remote attackers to execute arbitrary JavaScript in the context of authenticated users' browsers.

Critical Impact

Unauthenticated attackers can inject persistent malicious scripts that execute when administrators view booking records, potentially leading to admin session hijacking and account takeover.

Affected Products

• code-projects Home Service System 1.0
• Appointment Booking Component (/booking.php)

Discovery Timeline

• 2026-04-27 - CVE CVE-2026-7089 published to NVD
• 2026-04-29 - Last updated in NVD database

Technical Details for CVE-2026-7089

Vulnerability Analysis

This stored XSS vulnerability (CWE-79) allows unauthenticated remote attackers to inject malicious JavaScript code through the appointment booking form. The fname (first name) and lname (last name) input fields lack proper input validation and output encoding, allowing attackers to submit booking requests containing script payloads. When an administrator accesses the booking management interface to view appointments, the stored malicious scripts execute within their browser session.

The network-accessible nature of this vulnerability means any internet-facing deployment of the Home Service System is potentially at risk. While user interaction is required (an administrator must view the malicious booking entry), the persistence of the injected payload makes exploitation reliable once the initial injection succeeds.

Root Cause

The root cause is improper input validation and missing output encoding in the /booking.php file. The application directly stores user-supplied input from the fname and lname form fields into the database without sanitization, and subsequently renders this data in the administrative interface without proper HTML entity encoding. This allows HTML and JavaScript content to be interpreted as executable code rather than being treated as plain text data.

Attack Vector

The attack is initiated remotely over the network via the public-facing appointment booking form. An attacker crafts a booking request with malicious JavaScript embedded in the first name or last name fields. The payload is stored in the application database and executes when administrative users view the booking records. This creates an opportunity for session hijacking, credential theft, or administrative account takeover through techniques such as stealing session cookies or performing actions on behalf of the administrator.

The vulnerability mechanism involves submitting booking data containing JavaScript payloads in name fields. When administrators review bookings through the administrative interface, the unsanitized data is rendered directly into the HTML response, causing the browser to execute the injected scripts. For detailed technical information, refer to the GitHub Unauth Stored XSS Exploit repository.

Detection Methods for CVE-2026-7089

Indicators of Compromise

• Unusual JavaScript code or HTML tags present in booking database records (particularly in name fields)
• Booking entries containing <script>, onerror=, onload=, or similar event handlers in text fields
• Administrative session anomalies or unexpected logout events following booking record access
• Network requests to external domains originating from admin browser sessions while viewing bookings

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS payloads in form submissions
• Monitor database entries for common XSS patterns in user-input fields
• Deploy Content Security Policy (CSP) headers to restrict inline script execution and report violations
• Review web server access logs for POST requests to /booking.php containing suspicious encoded characters or script patterns

Monitoring Recommendations

• Enable CSP reporting to detect attempted script injection attacks
• Set up database auditing to flag entries containing HTML/JavaScript special characters in name fields
• Monitor administrative user sessions for signs of hijacking such as geographic anomalies or unusual activity patterns
• Implement real-time alerting for WAF XSS detection rules triggered on the booking endpoint

How to Mitigate CVE-2026-7089

Immediate Actions Required

• Implement strict input validation on all user-supplied form fields, rejecting or encoding special characters
• Apply HTML entity encoding to all user-supplied data before rendering in HTML contexts
• Deploy Content Security Policy headers with strict directives to prevent inline script execution
• Review existing booking records in the database for malicious content and sanitize or remove compromised entries

Patch Information

No official vendor patch has been published at this time. The vulnerability affects code-projects Home Service System 1.0, which is an educational/demonstration project available at Code Projects. Organizations using this software in production environments should implement manual mitigations or consider alternative solutions. Monitor VulDB Vulnerability #359664 for updates.

Workarounds

• Implement server-side input sanitization using functions like htmlspecialchars() in PHP for all user inputs before database storage
• Add output encoding when rendering any user-supplied data in HTML templates
• Restrict access to administrative interfaces to trusted networks or implement IP whitelisting
• Deploy a WAF with XSS protection rules in front of the application
• Consider disabling public booking functionality until proper input validation is implemented

# Example PHP input sanitization for booking.php
# Add these functions before storing user input:
# $fname = htmlspecialchars($_POST['fname'], ENT_QUOTES, 'UTF-8');
# $lname = htmlspecialchars($_POST['lname'], ENT_QUOTES, 'UTF-8');

# Example Content-Security-Policy header for Apache .htaccess
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'"