CVE-2026-1953: Nukegraphic CMS Stored XSS Vulnerability

CVE-2026-1953 Overview

A stored cross-site scripting (XSS) vulnerability has been identified in Nukegraphic CMS v3.1.2 within the user profile edit functionality. The application fails to properly sanitize user input in the name field at /ngc-cms/user-edit-profile.php before storing it in the database and rendering it across multiple CMS pages. An authenticated attacker with low privileges can inject malicious JavaScript payloads through the profile edit request, which are then executed site-wide whenever the affected user's name is displayed. This vulnerability enables arbitrary JavaScript execution in the context of other users' sessions, potentially leading to session hijacking, credential theft, or unauthorized actions performed on behalf of victims.

Critical Impact

Authenticated attackers can inject persistent malicious scripts that execute in the browsers of all users who view pages displaying the compromised user profile name, enabling widespread session hijacking and credential theft across the CMS.

Affected Products

• Nukegraphic CMS v3.1.2
• Nukegraphic CMS v3.x (earlier versions potentially affected)

Discovery Timeline

• February 5, 2026 - CVE-2026-1953 published to NVD
• February 5, 2026 - Last updated in NVD database

Technical Details for CVE-2026-1953

Vulnerability Analysis

This stored XSS vulnerability (CWE-79) exists due to improper neutralization of user-supplied input in the profile name field. When users update their profile information through the user-edit-profile.php endpoint, the application stores the name value directly in the database without adequate sanitization or encoding. Subsequently, when pages throughout the CMS render the user's name (such as in comments, author attribution, user lists, or activity logs), the malicious payload is executed in the browsers of users viewing those pages.

The attack requires authentication with low-level privileges, meaning any registered user on the CMS can potentially exploit this vulnerability. The network-accessible nature of the attack vector means it can be exploited remotely by any authenticated user. The stored nature of this XSS makes it particularly dangerous as the payload persists and affects all users who subsequently view pages displaying the compromised profile information.

Root Cause

The root cause of this vulnerability is the failure to implement proper input validation and output encoding within the Nukegraphic CMS user profile management functionality. Specifically, the application does not sanitize user-controlled input in the name field before database insertion, nor does it apply proper HTML entity encoding when rendering the stored data back to users. This violates the fundamental security principle of treating all user input as untrusted and encoding output appropriately for its rendering context.

Attack Vector

The attack is executed through the network by an authenticated user with minimal privileges. The attacker navigates to the profile edit functionality at /ngc-cms/user-edit-profile.php and submits a crafted payload containing malicious JavaScript in the name field. The attack requires user interaction from victims in the sense that they must view a page where the attacker's profile name is displayed. Once the victim's browser renders the page containing the malicious payload, the JavaScript executes in the victim's session context.

The attacker can craft payloads designed to steal session cookies, redirect users to phishing sites, perform actions on behalf of the victim, or inject keyloggers to capture credentials. Since the payload is stored persistently, every user who views the compromised content becomes a potential victim without any additional action required from the attacker.

For technical details and proof-of-concept information, refer to the GitHub PoC Repository.

Detection Methods for CVE-2026-1953

Indicators of Compromise

• Presence of JavaScript tags (<script>) or event handlers (onerror, onload, onclick) in user profile name fields in the database
• Unusual HTML entities or encoded script content in the name column of the users table
• Web application logs showing profile update requests containing script injection patterns
• Reports from users experiencing unexpected redirects or popup messages when viewing user-generated content

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block XSS payloads in profile update requests
• Deploy content security policy (CSP) headers with script-src directives to prevent inline script execution
• Configure intrusion detection systems (IDS) to alert on HTTP requests containing common XSS patterns targeting the /ngc-cms/user-edit-profile.php endpoint
• Perform regular database audits scanning for JavaScript or HTML markup in user profile fields

Monitoring Recommendations

• Enable verbose logging for all user profile modification requests and review for suspicious patterns
• Monitor browser-side JavaScript errors through error tracking services that may indicate blocked or failed XSS attempts
• Set up alerts for unusual patterns in session token usage that could indicate session hijacking
• Track Content-Security-Policy violation reports to identify XSS attack attempts in real-time

How to Mitigate CVE-2026-1953

Immediate Actions Required

• Review and sanitize all existing user profile name entries in the database to remove any injected scripts
• Implement strict input validation on the server-side to reject profile names containing HTML or script content
• Apply HTML entity encoding to all user-supplied data before rendering in HTML contexts
• Deploy Content-Security-Policy headers with strict script-src directives to mitigate the impact of any existing stored XSS

Patch Information

No official vendor patch information is currently available for CVE-2026-1953. Organizations using Nukegraphic CMS v3.1.2 should monitor the vendor's official channels for security updates and apply patches immediately upon release. Technical details regarding this vulnerability can be found in the GitHub PoC Repository.

Workarounds

• Implement a web application firewall (WAF) rule to filter XSS payloads in requests to /ngc-cms/user-edit-profile.php
• Restrict user profile editing capabilities to trusted administrators until a patch is available
• Deploy Content-Security-Policy headers with script-src 'self' to prevent execution of injected inline scripts
• Manually sanitize the database by removing script content from user profile name fields

# Example CSP header configuration for Apache
# Add to .htaccess or Apache configuration
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; frame-ancestors 'self';"

# Example CSP header configuration for Nginx
# Add to server block
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data:; frame-ancestors 'self';" always;