CVE-2026-6293: WordPress Inquiry Form Plugin CSRF Vulnerability

CVE-2026-6293 Overview

The Inquiry Form to Posts or Pages plugin for WordPress contains a Cross-Site Request Forgery (CSRF) vulnerability that chains with Stored Cross-Site Scripting (XSS) in version 1.0. This security flaw arises from missing nonce validation on the plugin settings update handler, combined with insufficient input sanitization on all user-supplied fields and missing output escaping when rendering stored values. Unauthenticated attackers can exploit this vulnerability to inject arbitrary web scripts by crafting a malicious request that tricks a logged-in Administrator into visiting a specially crafted page.

Critical Impact

Unauthenticated attackers can inject persistent malicious JavaScript into WordPress admin settings by exploiting missing CSRF protection and insufficient input sanitization, potentially leading to administrator session hijacking, privilege escalation, or complete site compromise.

Affected Products

• Inquiry Form to Posts or Pages WordPress Plugin version 1.0

Discovery Timeline

• 2026-04-15 - CVE CVE-2026-6293 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2026-6293

Vulnerability Analysis

This vulnerability represents a chained attack combining Cross-Site Request Forgery (CSRF) with Stored Cross-Site Scripting (XSS). The plugin's settings handler processes POST requests without implementing proper security controls that WordPress provides for protecting administrative actions. The handler executes solely based on checking if $_POST['inq_hidden'] == 'Y' is present, without calling check_admin_referer() or validating a WordPress nonce token.

The attack chain works as follows: an attacker crafts an HTML page containing a hidden form that submits malicious data to the vulnerable plugin endpoint. When an authenticated administrator visits this attacker-controlled page, their browser automatically submits the form using their authenticated session. Since no nonce validation exists, the plugin accepts the request and stores the attacker-supplied payload without proper sanitization. Subsequently, when the stored values are rendered in the admin panel, the malicious script executes in the context of the administrator's session.

Root Cause

The root cause is the complete absence of WordPress nonce validation in the plugin's settings update handler. The settings form lacks a wp_nonce_field() call, and the handler lacks a corresponding check_admin_referer() verification. This is compounded by missing input sanitization functions (such as sanitize_text_field(), esc_attr()) on user-supplied form data and missing output escaping functions (such as esc_html(), esc_attr()) when rendering stored values. The vulnerable code can be examined in the plugin settings handler at line 139 and form handling at line 60.

Attack Vector

The attack exploits the network attack vector and requires user interaction from an authenticated administrator. The attacker must craft a malicious HTML page that contains a form targeting the vulnerable WordPress plugin endpoint. When an administrator with an active WordPress session visits this page, the form auto-submits, storing the attacker's XSS payload in the plugin settings. The malicious script then executes whenever the settings page is viewed, enabling session hijacking, admin account creation, or arbitrary actions within the WordPress administrative context.

The vulnerability does not require prior authentication from the attacker - they only need to social engineer an administrator into visiting their malicious page while logged into WordPress.

Detection Methods for CVE-2026-6293

Indicators of Compromise

• Unexpected or unauthorized JavaScript code present in plugin settings fields
• Suspicious outbound requests from administrator browsers when viewing the plugin settings page
• Unexpected changes to the Inquiry Form plugin configuration without corresponding admin activity logs
• External iframe or script source references appearing in stored plugin options

Detection Strategies

• Monitor WordPress admin AJAX and POST requests for unusual patterns targeting the Inquiry Form plugin endpoints
• Implement Content Security Policy headers to detect and block unauthorized script execution
• Review browser developer console for JavaScript errors or unexpected script loading when accessing plugin settings
• Deploy web application firewall rules to detect XSS payloads in form submissions

Monitoring Recommendations

• Enable and review WordPress admin activity logging for all plugin settings changes
• Configure alerts for HTML or JavaScript content being stored in plugin option fields
• Monitor HTTP referrer headers on admin POST requests to identify potential CSRF attacks from external domains
• Implement integrity monitoring on WordPress database tables storing plugin options

How to Mitigate CVE-2026-6293

Immediate Actions Required

• Deactivate and remove the Inquiry Form to Posts or Pages plugin version 1.0 until a patched version is available
• Audit the WordPress database for any suspicious content stored in the plugin's settings
• Review WordPress admin accounts for unauthorized additions or privilege changes
• Force password resets for all administrator accounts that may have accessed the vulnerable plugin settings

Patch Information

No official patch is currently available for this vulnerability. The plugin developers should implement wp_nonce_field() in the settings form and check_admin_referer() in the handler, along with proper input sanitization using sanitize_text_field() and output escaping using esc_html() or esc_attr() where appropriate. Users should monitor the Wordfence vulnerability report for updates on patch availability.

Workarounds

• Remove the Inquiry Form to Posts or Pages plugin entirely until a security patch is released
• Restrict WordPress admin panel access to trusted IP addresses only via web server configuration or firewall rules
• Implement additional browser-based protections by using browser extensions that block CSRF attacks
• Use a Web Application Firewall (WAF) with rules to detect and block CSRF and XSS attack patterns

# Configuration example: Restrict WordPress admin access by IP in Apache .htaccess
# Place in wp-admin/.htaccess
<IfModule mod_authz_core.c>
    <RequireAny>
        Require ip 192.168.1.0/24
        Require ip 10.0.0.0/8
    </RequireAny>
</IfModule>