CVE-2026-42716 in Payever Plugin
Summary
by MITRE • 10/10/2026
Unauthenticated PHP Object Injection in Payever - WooCommerce Gateway <= 4.8.2 versions.
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Analysis
by VulDB Data Team • 10/10/2026
The vulnerability identified as an unauthenticated PHP object injection within the Payever payment gateway plugin for WordPress, specifically affecting versions up to and including 4.8.2, represents a critical security flaw that compromises the integrity of the underlying web application infrastructure. This type of vulnerability arises from improper handling of user-supplied input during the deserialization process, where data is converted back into PHP objects without adequate validation or sanitization. In the context of modern web applications, particularly those built on frameworks like WordPress which rely heavily on object-oriented programming paradigms for plugin architecture and core functionality, such flaws can be exploited by attackers to execute arbitrary code, escalate privileges, or manipulate application state in unintended ways. The absence of authentication requirements significantly amplifies the risk profile, as it allows any remote actor with network access to the target system to initiate an attack without needing valid credentials, thereby lowering the barrier for exploitation considerably and increasing the likelihood of successful compromise by automated scanning tools and opportunistic attackers alike.
From a technical perspective, PHP object injection typically occurs when functions such as unserialize are called on data derived from external sources like HTTP requests, cookies, or headers. If an attacker can control the input passed to these functions, they may craft a malicious serialized string that references existing classes within the application environment. By leveraging publicly available class definitions and magic methods—such as __wakeup, __destruct, or __toString—an adversary can trigger side effects during the deserialization process. These side effects might include file system operations like reading sensitive configuration files containing database credentials, writing web shells to persistent storage for backdoor access, or executing system commands through vulnerable library functions. In the specific case of the Payever WooCommerce gateway plugin, this flaw likely stems from insufficient checks on payment-related parameters or webhook responses that are processed by the application logic before being deserialized into internal objects. This lack of strict type checking and whitelist validation allows malicious payloads to bypass security controls embedded within the PHP runtime environment.
The operational impact of exploiting this vulnerability is severe and multifaceted, potentially leading to full system compromise depending on the execution context of the web server process. If the web service runs with elevated privileges or has access to sensitive directories, an attacker could exfiltrate customer payment data stored in the WordPress database, including credit card details if not properly tokenized by third-party processors, thereby violating PCI DSS compliance requirements and exposing merchants to significant financial liability and reputational damage. Furthermore, successful exploitation can result in defacement of the e-commerce storefront, disruption of business operations through denial-of-service conditions induced by resource exhaustion or logic errors caused by malformed objects, and use of the compromised server as a pivot point for further attacks against internal network resources. The unauthenticated nature means that even sites with strong administrative passwords remain vulnerable to automated botnet activity targeting known plugin vulnerabilities, making timely remediation essential for maintaining business continuity and trust among customers who expect secure transaction environments.
To mitigate this vulnerability, immediate action must be taken by upgrading the Payever WooCommerce Gateway plugin to version 4.8.3 or later, where the developers have presumably implemented proper input validation, strict type checking, and potentially switched from unsafe deserialization practices to safer alternatives such as JSON parsing for data exchange formats that do not support object instantiation in PHP. Administrators should also ensure that their WordPress core installation is up to date, as additional security patches may address related issues within the broader ecosystem. Implementing a Web Application Firewall can provide an additional layer of defense by detecting and blocking common exploitation patterns associated with serialized payloads before they reach the application logic. Additionally, enforcing principle of least privilege for web server processes ensures that even if an injection is successful, the potential damage to the underlying operating system is contained. Regular security audits and code reviews focusing on deserialization endpoints are recommended practices to prevent similar vulnerabilities from being introduced in future updates or other plugins within the same environment.
This vulnerability aligns with CWE-502, which describes Deserialization of Untrusted Data, a category recognized for its high severity due to the potential for remote code execution and privilege escalation. In terms of offensive security frameworks such as MITRE ATT&CK, this flaw facilitates techniques related to Initial Access via Exploit Public-Facing Application (T1190) and potentially Command and Control if backdoors are established through file system manipulation. Understanding these mappings helps organizations prioritize remediation efforts based on standardized risk assessments and ensures that defensive strategies are aligned with industry best practices for protecting web applications against sophisticated cyber threats targeting common open-source components like WordPress plugins.