CVE-2026-93940 in Greeny Plugin
Summary
by MITRE • 10/10/2026
Deserialization of Untrusted Data vulnerability in ThemeREX Group Greeny greeny allows Object Injection.This issue affects Greeny: from n/a through 2.10.0.
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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 Greeny theme developed by ThemeREX, specifically impacting versions ranging from initial releases up to version 2.10.0. This class of vulnerabilities arises when an application accepts serialized objects from external sources and processes them without adequate validation or sanitization. In this specific instance, the flaw allows for Object Injection, a severe security risk that enables attackers to manipulate internal object states by supplying maliciously crafted input data. The core technical issue lies in the theme's handling of user-supplied content during the deserialization process, where it fails to restrict the types of objects that can be instantiated or modified based on the incoming serialized stream.
From a technical perspective, this vulnerability is categorized under CWE-502, which denotes Deserialization of Untrusted Data. The mechanism typically involves an attacker crafting a payload containing a malicious object graph designed to exploit specific methods within Java classes available in the runtime environment. When the vulnerable application deserializes this input, it inadvertently executes arbitrary code or performs unintended operations defined by the injected objects. This bypasses standard authentication and authorization checks because the exploitation occurs at the level of object instantiation rather than through traditional access control mechanisms. The lack of strict type checking allows an attacker to instantiate classes that were not intended for public interaction, thereby gaining a foothold within the application's execution context.
The operational impact of this vulnerability is significant, as successful exploitation can lead to Remote Code Execution on the server hosting the vulnerable WordPress installation. An authenticated or unauthenticated attacker, depending on where the deserialization point is located within the theme's codebase, could potentially compromise the entire web server infrastructure. This may result in data exfiltration, defacement of the website, or using the compromised system as a pivot point for further attacks against internal networks. The severity is compounded by the widespread use of WordPress themes and the potential for automated scanning tools to detect and exploit this weakness across thousands of sites running affected versions of Greeny.
This vulnerability aligns with several techniques in the MITRE ATT&CK framework, particularly those related to Initial Access and Execution via Deserialization. Attackers often leverage such flaws during the initial compromise phase by injecting payloads through forms, API endpoints, or file uploads that are processed by the theme's backend logic. The ability to inject objects effectively allows for command execution similar to CWE-94 Improper Control of Generation of Code, highlighting the direct link between improper input handling and arbitrary code execution capabilities.
To mitigate this risk, administrators must immediately update the Greeny theme to a version later than 2.10.0 where the deserialization logic has been hardened or removed in favor of safer data interchange formats like JSON with strict schema validation. If updating is not immediately feasible, implementing Web Application Firewall rules that detect and block known malicious serialization payloads can provide temporary protection. Additionally, developers should review any custom code within child themes to ensure no similar patterns exist elsewhere in the installation. Enforcing least privilege principles for database users and web server processes further limits the potential damage if an exploitation attempt succeeds. Regular security audits focusing on input validation and output encoding are essential preventive measures against such deserialization flaws in future development cycles.