CVE-2026-6150: Simple Laundry System XSS Vulnerability

CVE-2026-6150 Overview

A Cross-Site Scripting (XSS) vulnerability has been identified in code-projects Simple Laundry System version 1.0. The vulnerability exists in the file /checkupdatestatus.php where improper handling of the serviceId argument allows attackers to inject malicious scripts. This flaw can be exploited remotely, and a public exploit has been disclosed.

Critical Impact

This XSS vulnerability enables remote attackers to execute arbitrary JavaScript code in victims' browsers, potentially leading to session hijacking, credential theft, or delivery of malicious content to end users of the Simple Laundry System application.

Affected Products

• code-projects Simple Laundry System 1.0
• /checkupdatestatus.php endpoint

Discovery Timeline

• 2026-04-13 - CVE-2026-6150 published to NVD
• 2026-04-13 - Last updated in NVD database

Technical Details for CVE-2026-6150

Vulnerability Analysis

This vulnerability is classified as CWE-79 (Improper Neutralization of Input During Web Page Generation), commonly known as Cross-Site Scripting. The affected component /checkupdatestatus.php fails to properly sanitize the serviceId parameter before including it in the rendered output. When user-supplied input is reflected back to the browser without adequate encoding or validation, an attacker can craft a malicious URL containing JavaScript that executes in the context of the victim's session.

The attack requires user interaction—specifically, a victim must click on or navigate to a specially crafted link containing the XSS payload. Once triggered, the injected script runs with the same privileges as the legitimate application, allowing attackers to access session tokens, modify page content, or redirect users to malicious sites.

Root Cause

The root cause of this vulnerability is insufficient input validation and output encoding in the /checkupdatestatus.php file. The serviceId parameter is accepted from user input and rendered directly in the HTTP response without proper sanitization. This allows HTML and JavaScript code to be injected and executed by the victim's browser when processing the server's response.

Attack Vector

The attack is network-based and can be initiated remotely. An attacker constructs a malicious URL containing JavaScript code in the serviceId parameter and distributes it to potential victims through phishing emails, social engineering, or injection into other web pages. When a victim clicks the link and the vulnerable page renders, the malicious script executes within their browser session.

The vulnerability affects the serviceId parameter in /checkupdatestatus.php. An attacker can craft a URL containing JavaScript code in this parameter. When a victim accesses the malicious link, the script executes in their browser context, potentially allowing session hijacking or data theft. For detailed technical information, refer to the GitHub CVE Issue Discussion and VulDB Vulnerability #357030.

Detection Methods for CVE-2026-6150

Indicators of Compromise

• Unusual requests to /checkupdatestatus.php containing <script> tags, event handlers (e.g., onerror, onclick), or encoded JavaScript in the serviceId parameter
• HTTP access logs showing URL-encoded payloads such as %3Cscript%3E or javascript: in query strings
• Client-side console errors or unexpected JavaScript execution originating from the application domain
• Reports from users of unexpected behavior, pop-ups, or redirects when using the laundry system

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block common XSS patterns in the serviceId parameter
• Implement Content Security Policy (CSP) headers to restrict inline script execution and report violations
• Monitor server access logs for requests containing suspicious characters or patterns in URL parameters
• Use browser-based XSS auditors or security extensions to identify reflected content

Monitoring Recommendations

• Enable detailed logging for all requests to /checkupdatestatus.php and review for anomalous input patterns
• Configure alerts for high volumes of requests containing HTML special characters in parameters
• Regularly audit application logs for signs of exploitation attempts or suspicious activity
• Implement runtime application self-protection (RASP) to detect script injection attempts

How to Mitigate CVE-2026-6150

Immediate Actions Required

• Apply output encoding to the serviceId parameter before rendering in HTML context
• Implement server-side input validation to reject or sanitize unexpected characters in serviceId
• Deploy Content Security Policy (CSP) headers with strict policies to mitigate impact of successful XSS
• Consider disabling or restricting access to /checkupdatestatus.php until a patch is applied

Patch Information

As of the last NVD update on 2026-04-13, no official vendor patch has been released for code-projects Simple Laundry System 1.0. Organizations using this software should monitor the Code Projects Overview page for updates. In the interim, apply the workarounds and mitigations described below.

Workarounds

• Implement input validation on the serviceId parameter to allow only expected values (e.g., numeric IDs)
• Apply HTML entity encoding to all user-supplied input before rendering in the response
• Deploy a Web Application Firewall (WAF) with XSS detection rules in front of the application
• Restrict network access to the application to trusted users only until a permanent fix is available

# Example Apache mod_security rule to block XSS in serviceId parameter
SecRule ARGS:serviceId "@rx (?i)(<script|javascript:|on\w+\s*=)" \
    "id:100001,phase:2,deny,status:403,msg:'XSS attempt blocked in serviceId'"