CVE-2026-106606 in WooCommerce Affiliates Plugin
Summary
by MITRE • 10/10/2026
Deserialization of Untrusted Data vulnerability in YITH YITH WooCommerce Affiliates yith-woocommerce-affiliates allows Object Injection.This issue affects YITH WooCommerce Affiliates: from n/a through 3.31.0.
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Analysis
by VulDB Data Team • 10/10/2026
The identified security flaw represents a critical deserialization of untrusted data vulnerability within the YITH WooCommerce Affiliates plugin, specifically affecting versions ranging from initial releases up to version 3.31.0. This type of vulnerability arises when an application accepts serialized objects from external sources without adequate validation or sanitization before processing them. In this specific context, the flaw allows for object injection, which is a severe security risk that can lead to remote code execution if exploited effectively. The core issue lies in the plugin's handling of data inputs where it fails to restrict the types of objects that can be instantiated during the unserialization process, thereby trusting potentially malicious payloads provided by attackers.
From a technical perspective, this vulnerability aligns with CWE-502, which describes deserialization of untrusted data as a weakness allowing attackers to manipulate object states or execute arbitrary code through crafted serialized strings. When an application processes these objects, it may invoke dangerous methods such as __wakeup(), __destruct(), or other magic methods that are registered in the PHP environment. If the plugin does not implement strict whitelisting of allowed classes or utilize secure serialization mechanisms like JSON instead of native PHP serialize functions, attackers can craft payloads that trigger unintended side effects within the application's runtime environment. This often involves leveraging gadget chains—sequences of existing code snippets—to achieve arbitrary command execution on the server hosting the WordPress instance.
The operational impact of this vulnerability is significant for any e-commerce site running the affected versions of YITH WooCommerce Affiliates. Successful exploitation could allow an attacker to gain unauthorized access to the underlying system, potentially leading to full compromise of the web server. This might result in data theft, including sensitive customer information and affiliate commission records stored within the WordPress database. Furthermore, attackers could use this entry point to install backdoors, deface the website, or pivot into other parts of the network infrastructure if the server is not properly isolated. The severity is compounded by the fact that many WordPress plugins are accessible via standard HTTP requests without requiring high-level administrative privileges for certain endpoints, although some deserialization vectors may require authenticated access depending on how the specific input fields are exposed in the plugin's interface.
Mitigation strategies must focus on immediate remediation and long-term defensive coding practices. The primary recommendation is to update YITH WooCommerce Affiliates to a version later than 3.31.0, where this vulnerability has been patched by implementing stricter validation checks or removing insecure deserialization calls entirely. For organizations unable to patch immediately due to compatibility constraints, temporary mitigations include restricting file uploads and input parameters through web application firewalls that can detect known malicious serialized payloads. Additionally, developers should audit the codebase for any custom functions relying on unserialize() without proper class whitelisting and replace them with safer alternatives like json_decode(). Regular security audits and adherence to secure coding standards such as OWASP guidelines are essential to prevent similar vulnerabilities in future development cycles.
This incident underscores the importance of rigorous input validation and output encoding in web application development, particularly when dealing with complex data structures like serialized objects. Security teams should monitor for any signs of exploitation attempts through server logs and ensure that all third-party plugins are kept up-to-date to minimize the attack surface. By addressing this vulnerability promptly, administrators can protect their e-commerce platforms from potential compromise and maintain the integrity of their affiliate programs and customer data.