CVE-2026-22349: Menu In Post DOM-Based XSS Vulnerability

CVE-2026-22349 Overview

CVE-2026-22349 is a DOM-Based Cross-Site Scripting (XSS) vulnerability affecting the Menu In Post WordPress plugin developed by linux4me2. This vulnerability stems from improper neutralization of input during web page generation, allowing attackers to inject malicious scripts that execute in the context of a victim's browser session.

DOM-Based XSS vulnerabilities occur when client-side JavaScript processes untrusted data and writes it to the DOM without proper sanitization. Unlike reflected or stored XSS, the malicious payload never reaches the server, making traditional server-side protections ineffective.

Critical Impact

Attackers can execute arbitrary JavaScript in victim browsers, potentially stealing session cookies, credentials, or performing actions on behalf of authenticated users on WordPress sites using this plugin.

Affected Products

• Menu In Post WordPress Plugin version 1.4.1 and earlier
• WordPress installations with Menu In Post plugin enabled

Discovery Timeline

• 2026-01-22 - CVE-2026-22349 published to NVD
• 2026-01-22 - Last updated in NVD database

Technical Details for CVE-2026-22349

Vulnerability Analysis

This vulnerability is classified as CWE-79: Improper Neutralization of Input During Web Page Generation (Cross-site Scripting). The Menu In Post plugin fails to properly sanitize user-controlled input before incorporating it into the DOM through client-side JavaScript operations.

In DOM-Based XSS attacks, the vulnerability exists entirely within the browser's client-side code. The plugin's JavaScript reads data from sources such as URL parameters, document location, or other DOM elements and passes this data to dangerous sinks like innerHTML, document.write(), or eval() without adequate encoding or validation.

When exploited, attackers can craft malicious URLs or input that, when processed by the vulnerable JavaScript code, results in script execution within the user's browser context. This can lead to session hijacking, credential theft, defacement, or redirection to malicious sites.

Root Cause

The root cause of this vulnerability is insufficient input validation and output encoding in the plugin's client-side JavaScript code. The Menu In Post plugin processes user-controlled data and renders it to the page DOM without implementing proper HTML entity encoding or JavaScript escaping mechanisms.

WordPress plugins that manipulate menu content dynamically are particularly susceptible to DOM-Based XSS when they fail to use secure DOM manipulation methods such as textContent instead of innerHTML, or when they don't properly sanitize data before insertion.

Attack Vector

The attack vector for this DOM-Based XSS vulnerability typically involves crafting a malicious URL containing JavaScript payload in parameters that are processed by the vulnerable plugin code. An attacker would distribute this URL through phishing emails, social media, or other channels. When a victim clicks the link while authenticated to a WordPress site using the vulnerable plugin, the malicious script executes with the victim's session privileges.

The vulnerability can be exploited without authentication to the WordPress site, as the malicious payload is processed client-side. However, the impact is most severe when targeting authenticated administrators, as this could lead to complete site compromise.

For detailed technical information about this vulnerability, refer to the Patchstack WordPress Vulnerability Report.

Detection Methods for CVE-2026-22349

Indicators of Compromise

• Unusual JavaScript execution patterns in browser developer tools console
• Unexpected outbound requests to external domains from WordPress pages using the Menu In Post plugin
• Reports from users about suspicious pop-ups or redirects on pages containing menus rendered by the plugin
• Web application firewall logs showing XSS payload patterns in URL parameters

Detection Strategies

• Implement Content Security Policy (CSP) headers to detect and block inline script execution
• Monitor browser console errors for DOM manipulation anomalies
• Deploy web application firewalls with XSS signature detection capabilities
• Conduct regular security scans using WordPress vulnerability scanners that check for known plugin vulnerabilities

Monitoring Recommendations

• Enable verbose logging on web application firewalls to capture potential XSS attempts
• Monitor for unusual URL patterns containing encoded script tags or JavaScript event handlers
• Implement client-side monitoring solutions to detect DOM manipulation attempts
• Review access logs for requests containing common XSS payloads targeting plugin endpoints

How to Mitigate CVE-2026-22349

Immediate Actions Required

• Update the Menu In Post plugin to the latest available version that addresses this vulnerability
• If no patch is available, consider temporarily disabling the Menu In Post plugin until a fix is released
• Implement Content Security Policy headers to mitigate XSS impact
• Review and restrict plugin permissions to limit potential damage from exploitation

Patch Information

Organizations should monitor the official WordPress plugin repository and the Patchstack security database for updates addressing this vulnerability. Plugin versions through 1.4.1 are confirmed vulnerable.

If an updated version is available, update immediately through the WordPress admin dashboard under Plugins > Updates, or by downloading the latest version from the WordPress plugin repository.

Workarounds

• Implement a strict Content Security Policy that blocks inline scripts and restricts script sources to trusted domains
• Use a Web Application Firewall (WAF) with XSS filtering capabilities to block malicious payloads
• Consider using alternative menu plugins until a security patch is released
• Restrict administrative access to WordPress and limit the number of users who can modify menu configurations

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

# Example: Add CSP header in Nginx configuration
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'";