CVE-2025-26543: Simple Responsive Menu CSRF Vulnerability

CVE-2025-26543 Overview

CVE-2025-26543 is a Cross-Site Request Forgery (CSRF) vulnerability in the Simple Responsive Menu WordPress plugin developed by Pukhraj Suthar. This security flaw allows attackers to chain CSRF with Stored Cross-Site Scripting (XSS), enabling malicious actors to inject persistent scripts into the vulnerable WordPress installation through forged requests.

Critical Impact

Attackers can exploit this vulnerability to trick authenticated administrators into unknowingly injecting malicious scripts that persist in the WordPress database, potentially compromising site visitors and administrative accounts.

Affected Products

• Simple Responsive Menu WordPress Plugin version 2.1 and earlier
• WordPress installations with Simple Responsive Menu (simple-responsive-menu) activated

Discovery Timeline

• 2025-02-13 - CVE-2025-26543 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2025-26543

Vulnerability Analysis

This vulnerability combines two attack vectors: Cross-Site Request Forgery (CSRF) and Stored Cross-Site Scripting (XSS). The Simple Responsive Menu plugin fails to implement proper CSRF token validation on administrative forms that handle menu configuration settings. This oversight allows attackers to craft malicious web pages that, when visited by an authenticated WordPress administrator, can submit forged requests to the plugin's settings endpoints.

The absence of proper input sanitization on these settings fields further compounds the vulnerability, enabling the injection of malicious JavaScript code that persists in the WordPress database. When legitimate users subsequently access pages where the menu is rendered, the stored XSS payload executes in their browser context.

Root Cause

The root cause of CVE-2025-26543 stems from two critical security failures in the Simple Responsive Menu plugin:

1. Missing CSRF Protection: The plugin's administrative settings forms do not implement WordPress nonce verification, allowing cross-origin requests to modify plugin settings without proper authorization checks.

2. Insufficient Input Sanitization: User-supplied input to menu configuration fields is not properly sanitized or escaped before being stored in the database and subsequently rendered in the frontend, enabling stored XSS attacks.

Attack Vector

The attack requires an authenticated WordPress administrator to visit a malicious webpage controlled by the attacker while logged into the target WordPress installation. The attack flow proceeds as follows:

1. The attacker crafts a malicious HTML page containing a hidden form that targets the vulnerable plugin's settings endpoint
2. The form is automatically submitted via JavaScript when the victim administrator visits the attacker's page
3. The forged request contains malicious JavaScript payloads in the menu configuration fields
4. Due to missing CSRF validation, WordPress processes the request as legitimate
5. The malicious script is stored in the database and executed whenever the affected menu is rendered

The vulnerability can be exploited without requiring any special privileges on the target WordPress site, though it does require social engineering to trick an administrator into visiting the malicious page.

Detection Methods for CVE-2025-26543

Indicators of Compromise

• Unexpected modifications to Simple Responsive Menu plugin settings
• Suspicious JavaScript code embedded in menu configuration database entries
• Reports of browser security warnings or unexpected script execution from site visitors
• Unusual administrator session activity following visits to external websites

Detection Strategies

• Review the wp_options table for Simple Responsive Menu settings containing unexpected script tags or JavaScript event handlers
• Monitor WordPress admin activity logs for settings changes without corresponding admin panel access
• Implement Content Security Policy (CSP) headers to detect and block inline script execution attempts
• Deploy web application firewalls (WAF) configured to detect XSS payloads in request bodies

Monitoring Recommendations

• Enable comprehensive WordPress audit logging to track all plugin settings modifications
• Configure alerts for changes to Simple Responsive Menu configuration options
• Implement browser-based XSS detection using CSP violation reporting
• Regularly scan WordPress database for indicators of stored XSS payloads

How to Mitigate CVE-2025-26543

Immediate Actions Required

• Deactivate and remove the Simple Responsive Menu plugin until a patched version is available
• Review and sanitize any existing Simple Responsive Menu configuration data in the WordPress database
• Implement a Web Application Firewall (WAF) with CSRF and XSS protection rules
• Educate WordPress administrators about the risks of visiting untrusted websites while logged into the admin panel

Patch Information

As of the published CVE information, Simple Responsive Menu versions through 2.1 are affected. Administrators should monitor the Patchstack vulnerability database for updates regarding available patches. Until a security update is released, the plugin should be deactivated.

Workarounds

• Remove or deactivate the Simple Responsive Menu plugin entirely until a security patch is released
• Implement server-level request filtering to block suspicious POST requests to the plugin's settings endpoints
• Use a security plugin that provides CSRF protection for vulnerable plugins
• Restrict WordPress admin access to trusted IP addresses to limit the attack surface
• Consider migrating to an alternative responsive menu plugin with active security maintenance

For WordPress administrators, database cleanup can be performed by inspecting the options table for Simple Responsive Menu entries. Review any stored configuration values and remove suspicious script tags or event handlers. Always maintain current database backups before making manual modifications.