CVE-2026-93937 in Hygia Plugin
Summary
by MITRE • 10/10/2026
Deserialization of Untrusted Data vulnerability in ThemeREX Group Hygia hygia allows Object Injection.This issue affects Hygia: from n/a through 1.21.0.
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Analysis
by VulDB Data Team • 10/10/2026
The identified vulnerability represents a critical security flaw within the ThemeREX Group Hygia application, specifically categorized as an insecure deserialization of untrusted data leading to object injection. This type of vulnerability arises when an application accepts serialized objects from external sources without adequate validation or sanitization before processing them. In the context of Java-based applications like Hygia, which likely utilizes frameworks such as Apache Commons Collections or similar serialization libraries, this flaw allows attackers to manipulate the deserialization process. When a user provides maliciously crafted input that has been serialized into an object graph, the application's internal mechanisms may instantiate these objects and execute their methods during the unmarshaling phase. This behavior bypasses standard security controls because the code execution is triggered by the framework itself rather than through direct function calls from the developer, making it a potent attack vector for remote code execution.
The technical mechanism behind this vulnerability relies on the ability of an attacker to construct a gadget chain using classes available in the application's classpath. By carefully selecting specific library classes that have side effects during their deserialization or method invocation, such as those involving reflection, template engines, or command execution utilities, an adversary can create a payload that performs arbitrary actions once deserialized. The vulnerability affects versions of Hygia from n/a through version 1.21.0, indicating that any deployment running these older iterations is susceptible to exploitation if the vulnerable endpoint accepts user-controlled input for deserialization purposes. This often occurs in endpoints handling API requests, file uploads, or configuration updates where serialized data formats like JSON with specific extensions or Java native serialization are processed without strict type checking or allow-listing of permitted classes.
From an operational perspective, the impact of this vulnerability is severe and potentially catastrophic. Successful exploitation allows a remote attacker to achieve arbitrary code execution on the server hosting the Hygia application. This can lead to full system compromise, where the attacker gains control over the underlying operating system, accesses sensitive data stored within the database or file system, and uses the compromised host as a pivot point for further attacks against internal network resources. Additionally, attackers may modify application logic, inject backdoors, or disrupt service availability by causing crashes through malformed object graphs. The lack of input validation means that even authenticated users with low privileges could potentially exploit this flaw if they have access to any interface that processes serialized data, thereby escalating their privileges and undermining the integrity of the entire platform.
To mitigate this risk, immediate action is required for all systems running Hygia versions up to 1.21.0. The primary remediation strategy involves upgrading to a patched version of the software where ThemeREX Group has addressed the insecure deserialization logic by implementing strict allow-lists for permitted classes during deserialization or switching to safer serialization formats that do not support arbitrary object instantiation, such as standard JSON without custom type handlers. If an upgrade is not immediately feasible, administrators should implement network-level controls such as Web Application Firewalls configured with rulesets specifically designed to detect and block known gadget chains associated with common Java deserialization vulnerabilities. Furthermore, disabling unnecessary features or endpoints that handle serialized data can reduce the attack surface. It is also advisable to review application logs for signs of exploitation attempts, which often manifest as unusual stack traces involving reflection or specific library classes during request processing.
This vulnerability aligns closely with CWE-502, Deserialization of Untrusted Data, and falls under the MITRE ATT&CK technique T1190, Exploit Public-Facing Application. The attack pattern typically involves reconnaissance to identify vulnerable endpoints followed by exploitation via payload delivery through HTTP requests or other network protocols. Security teams should prioritize patching this issue due to its high severity rating in most vulnerability scoring systems and its potential for widespread impact across enterprise environments utilizing Hygia for dashboarding and analytics. Regular security assessments, including static application security testing focused on serialization practices and dynamic penetration testing targeting input validation boundaries, are recommended to ensure that similar flaws do not persist in future updates or related components within the ecosystem.