CVE-2026-112858 in Rhodos Plugin
Summary
by MITRE • 10/23/2026
Deserialization of Untrusted Data vulnerability in axiomthemes Rhodos rhodos allows Object Injection.This issue affects Rhodos: from n/a through 1.3.3.
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Analysis
by VulDB Data Team • 10/23/2026
The identified vulnerability represents a critical security flaw within the Rhodos theme developed by AxiomThemes, specifically affecting versions ranging from initial releases up to version 1.3.3. This issue is classified as a Deserialization of Untrusted Data vulnerability, which falls under the broader category of Object Injection attacks. In web application architecture, deserialization refers to the process of converting serialized data back into its original object structure for use within an application's memory space. When this process involves data that has not been adequately validated or sanitized by the user, it creates a significant attack vector where malicious actors can manipulate the input stream to inject arbitrary objects rather than benign data structures.
The technical mechanism behind this flaw relies on the inherent dangers of PHP deserialization functions such as unserialize(), which are commonly used in WordPress themes and plugins to restore state from cookies, POST parameters, or other user-controlled inputs. If a developer fails to implement strict type checking or allow-listing for expected object classes before invoking these functions, an attacker can craft a serialized payload containing malicious objects. These objects may exploit magic methods like __wakeup(), __destruct(), or __toString() that are triggered automatically during the deserialization process. By carefully constructing this payload, an adversary can achieve remote code execution, arbitrary file inclusion, denial of service conditions, or privilege escalation depending on the available classes and their implementations within the theme's environment.
From a classification perspective, this vulnerability aligns with CWE-502, which denotes Deserialization of Untrusted Data. This weakness is particularly dangerous because it often bypasses traditional input validation checks that focus solely on string content rather than object structure or class instantiation logic. Furthermore, in terms of offensive security frameworks such as MITRE ATT&CK, this technique maps to T1190 Exploit Public-Facing Application and potentially T1059 Command and Scripting Interpreter if the deserialization leads directly to code execution. The ability to inject objects allows attackers to interact with internal application logic in unintended ways, effectively turning legitimate features into tools for compromise.
The operational impact of this vulnerability is severe, particularly given that Rhodos is a widely used theme within the WordPress ecosystem. Successful exploitation could allow an unauthenticated attacker or even a low-privileged user, such as a subscriber, to execute arbitrary code on the server hosting the website. This can lead to complete system compromise, including theft of sensitive data, defacement of the site, installation of web shells for persistent access, and use of the compromised server as part of a botnet. The widespread adoption of older versions means that many sites remain exposed if they have not applied timely updates or implemented additional security controls.
Mitigation strategies must prioritize immediate remediation through software updates. Administrators should upgrade Rhodos to version 1.3.4 or later, where the vendor has presumably addressed this flaw by implementing safer deserialization practices such as using json_decode() instead of unserialize(), enforcing strict type checking on input data, and utilizing allow-lists for permitted classes during object restoration. For sites that cannot immediately update due to compatibility constraints, temporary mitigations include disabling PHP functions like unserialize() if not strictly necessary, configuring web application firewalls to detect known malicious serialized payloads, and restricting file permissions to limit the impact of any potential code execution. Regular security audits and adherence to secure coding standards are essential to prevent similar vulnerabilities in future development cycles.