CVE-2026-93943 in Convex Plugin
Summary
by MITRE • 10/10/2026
Deserialization of Untrusted Data vulnerability in ThemeREX Group Convex convex allows Object Injection.This issue affects Convex: from n/a through 1.16.0.
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Analysis
by VulDB Data Team • 10/10/2026
The identified security flaw represents a critical deserialization vulnerability within the ThemeREX Group Convex WordPress theme, specifically affecting versions ranging from initial releases up to version 1.16.0. This category of vulnerability arises when an application processes untrusted data without adequate validation or sanitization prior to passing it to a deserialization function. In this specific instance, the flaw permits Object Injection, which is a severe security risk that allows attackers to manipulate internal object states and potentially execute arbitrary code on the server hosting the vulnerable website. The core technical issue lies in the theme's handling of user-supplied input during administrative operations or data processing routines where serialized PHP objects are reconstructed into executable memory structures without verifying their integrity or origin.
From a technical perspective, this vulnerability is classified under CWE-502, which denotes Deserialization of Untrusted Data. The attack vector typically involves an authenticated attacker with low privileges, such as a subscriber or contributor role within the WordPress environment, who can inject maliciously crafted serialized payloads into fields that are subsequently processed by the theme's backend logic. When the application deserializes this input, it instantiates objects defined in the payload rather than standard data structures. If the server has accessible gadget chains—sequences of existing PHP classes whose methods can be chained together to perform unintended actions—the attacker can leverage these gadgets to achieve Remote Code Execution (RCE). This bypasses traditional authentication and authorization controls because the execution occurs within the context of the web application process, often with elevated privileges depending on how the theme interacts with WordPress core functions.
The operational impact of this vulnerability is profound, as it compromises the confidentiality, integrity, and availability of the affected system. Successful exploitation allows an attacker to gain full control over the underlying server environment hosting the website. This can lead to complete site defacement, theft of sensitive user data including credentials and personal information stored in the database, or the installation of backdoors for persistent access. Furthermore, compromised websites are frequently repurposed as nodes in botnets used for distributed denial-of-service attacks, phishing campaigns, or malware distribution networks. The presence of such a vulnerability significantly undermines trust in the platform and exposes organizations to regulatory penalties under data protection laws if customer data is exfiltrated due to inadequate security controls within third-party plugins or themes.
In terms of industry frameworks, this incident aligns with MITRE ATT&CK technique T1059, specifically Command and Scripting Interpreter sub-techniques such as PHP (T1059.007), where attackers use scripting languages like PHP to execute commands on the target system. It also relates to T1190, Exploit Public-Facing Application, indicating that the vulnerability is accessible through services exposed to external networks or authenticated users via the web interface. The lack of strict input validation and type checking during deserialization processes exemplifies a failure in secure coding practices recommended by OWASP, particularly regarding insecure direct object references and improper handling of serialized data streams.
To mitigate this risk, immediate action must be taken by administrators using affected versions of the Convex theme. The primary remediation step is to upgrade the theme to version 1.16.1 or later, where the developers have presumably implemented stricter input validation and disabled dangerous deserialization functions for untrusted inputs. If upgrading is not immediately feasible, temporary mitigations include restricting user roles that can submit data processed by the vulnerable components, implementing a Web Application Firewall (WAF) to detect and block known malicious serialized payloads based on signature patterns, and disabling PHP execution in directories where theme files are stored if possible. Regular security audits and code reviews focusing on deserialization practices should be conducted to prevent similar vulnerabilities from being introduced in future updates or custom modifications of the theme.