CVE-2026-102108 in Email Protection Gateway
Summary
by MITRE • 10/01/2026
An authenticated administrator of Kiteworks Email Protection Gateway could submit a crafted serialized object to a cluster management interface that was deserialized without sufficient validation, potentially allowing arbitrary code execution in the context of the gateway service account. Exploitation requires an administrator account holding a specific queue-management privilege.
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Analysis
by VulDB Data Team • 10/01/2026
The vulnerability identified involves a critical insecure deserialization flaw within the Kiteworks Email Protection Gateway cluster management interface. This security issue stems from the application's handling of serialized Java objects, where user-supplied input is processed without adequate validation or sanitization before being passed to the object reconstruction mechanism. Insecure deserialization occurs when untrusted data is used during the deserialization process, allowing an attacker to manipulate the type and content of reconstructed objects. This manipulation can lead to a wide range of adverse impacts, including replay attacks, injection attacks, privilege escalation, denial of service, and remote code execution. The specific implementation flaw in this gateway allows for the submission of crafted serialized payloads that exploit weaknesses in how the cluster management interface processes these inputs, bypassing standard security controls designed to prevent such manipulations.
The operational impact of this vulnerability is severe due to its potential for arbitrary code execution within the context of the gateway service account. This level of access grants an attacker significant control over the underlying system hosting the Kiteworks Email Protection Gateway. By achieving remote code execution, a malicious actor could potentially compromise the integrity and confidentiality of email communications processed by the gateway. They might intercept sensitive data, modify message content, or use the compromised server as a pivot point to attack other systems within the network infrastructure. The severity is further amplified because exploitation requires an authenticated administrator account with specific queue-management privileges, which suggests that while initial access requires credentials, those credentials are often held by individuals who manage critical email infrastructure components, thereby increasing the likelihood of successful exploitation in targeted attacks.
From a classification perspective, this vulnerability aligns closely with CWE-502, Deserialization of Untrusted Data, and potentially CWE-94, Improper Control of Generation of Code (Code Injection), as it allows for arbitrary code execution through manipulated object states. In terms of the MITRE ATT&CK framework, this flaw facilitates techniques associated with Initial Access via Valid Accounts and Execution via Command and Scripting Interpreter or Native API, depending on how the deserialized payload is constructed to execute commands. The requirement for an administrator account places this within the context of privilege abuse, highlighting the importance of strict access control policies even for administrative roles that handle specific functional areas like queue management.
Mitigation strategies must focus on both immediate remediation and long-term architectural improvements. Administrators should immediately apply any available patches or updates provided by Kiteworks that address this deserialization vulnerability in the cluster management interface. If patching is not immediately feasible, network-level controls such as firewalls can be configured to restrict access to the affected API endpoints solely from trusted administrative IP addresses, thereby reducing the attack surface. Additionally, implementing strict input validation and ensuring that only whitelisted object types are allowed during deserialization processes can prevent exploitation of similar flaws in other components. It is also crucial to enforce the principle of least privilege by reviewing administrator accounts with queue-management privileges, ensuring they have access only to what is strictly necessary for their operational duties. Regular security audits and penetration testing focused on API endpoints and serialization mechanisms will help identify and remediate such vulnerabilities before they can be exploited in production environments.