A Vulnerability in Kiteworks EPG (Email Security Gateway) Could Allow for Arbitrary Code Execution

A vulnerability has been discovered in Kiteworks EPG (Email Security Gateway) that could allow for arbitrary code execution. Kiteworks Email Protection Gateway (EPG) is a cloud-based security solution that automates end-to-end encryption, decryption, and policy enforcement for inbound and outbound enterprise emails. A combination of input-handling flaws in publicly reachable endpoints of the Kiteworks Email Protection Gateway may potentially allow an unauthenticated remote attacker to achieve arbitrary code execution. Successful exploitation of this vulnerability could allow for arbitrary code execution as root, which may lead to the complete compromise of the affected device.

There are currently no reports of this vulnerability being exploited in the wild.

A vulnerability has been discovered in Kiteworks EPG (Email Security Gateway) that could allow for arbitrary code execution. Details of the vulnerability are as follows:

Tactic: Initial Access (TA0001)

Technique: Exploit Public-Facing Application (T1190)

• A combination of input-handling flaws in publicly reachable endpoints of the Kiteworks Email Protection Gateway potentially allowed an unauthenticated remote attacker to achieve arbitrary code execution and, by chaining additional local weaknesses, to escalate to full administrative (root) control of the appliance (CVE-2026-54154)

Successful exploitation of this vulnerability could allow for arbitrary code execution as root, which may lead to the complete compromise of the affected device.

We recommend the following actions be taken:

• Apply appropriate updates provided by Kiteworks to vulnerable systems immediately after appropriate testing. (M1051: Update Software)
• Safeguard 7.1: Establish and Maintain a Vulnerability Management Process: Establish and maintain a documented vulnerability management process for enterprise assets. Review and update documentation annually, or when significant enterprise changes occur that could impact this Safeguard.
• Safeguard 7.2: Establish and Maintain a Remediation Process: Establish and maintain a risk-based remediation strategy documented in a remediation process, with monthly, or more frequent, reviews.
• Safeguard 7.4: Perform Automated Application Patch Management: Perform application updates on enterprise assets through automated patch management on a monthly, or more frequent, basis.
• Safeguard 7.7: Remediate Detected Vulnerabilities: Remediate detected vulnerabilities in software through processes and tooling on a monthly, or more frequent, basis, based on the remediation process.
• Safeguard 12.1: Ensure Network Infrastructure is Up-to-Date: Ensure network infrastructure is kept up-to-date. Example implementations include running the latest stable release of software and/or using currently supported network-as-a-service (NaaS) offerings. Review software versions monthly, or more frequently, to verify software support.

• Vulnerability scanning is used to find potentially exploitable software vulnerabilities to remediate them. (M1016: Vulnerability Scanning)
• Safeguard 16.13: Conduct Application Penetration Testing: Conduct application penetration testing. For critical applications, authenticated penetration testing is better suited to finding business logic vulnerabilities than code scanning and automated security testing. Penetration testing relies on the skill of the tester to manually manipulate an application as an authenticated and unauthenticated user.
• Safeguard 18.1: Establish and Maintain a Penetration Testing Program: Establish and maintain a penetration testing program appropriate to the size, complexity, and maturity of the enterprise. Penetration testing program characteristics include scope, such as network, web application, Application Programming Interface (API), hosted services, and physical premise controls; frequency; limitations, such as acceptable hours, and excluded attack types; point of contact information; remediation, such as how findings will be routed internally; and retrospective requirements.
• Safeguard 18.3: Remediate Penetration Test Findings: Remediate penetration test findings based on the enterprise’s policy for remediation scope and prioritization.

• Apply the Principle of Least Privilege to all systems and services. Run all software as a non-privileged user (one without administrative privileges) to diminish the effects of a successful attack. (M1026: Privileged Account Management)
• Safeguard 4.7: Manage Default Accounts on Enterprise Assets and Software: Manage default accounts on enterprise assets and software, such as root, administrator, and other pre-configured vendor accounts. Example implementations can include: disabling default accounts or making them unusable.
• Safeguard 5.5: Establish and Maintain an Inventory of Service Accounts: Establish and maintain an inventory of service accounts. The inventory, at a minimum, must contain department owner, review date, and purpose. Perform service account reviews to validate that all active accounts are authorized, on a recurring schedule at a minimum quarterly, or more frequently.

• Architect sections of the network to isolate critical systems, functions, or resources. Use physical and logical segmentation to prevent access to potentially sensitive systems and information. Use a DMZ to contain any internet-facing services that should not be exposed from the internal network. Configure separate virtual private cloud (VPC) instances to isolate critical cloud systems. (M1030: Network Segmentation)
• Safeguard 12.2: Establish and Maintain a Secure Network Architecture: Establish and maintain a secure network architecture. A secure network architecture must address segmentation, least privilege, and availability, at a minimum.
• Safeguard 12.8: Establish and Maintain Dedicated Computing Resources for All Administrative Work: Establish and maintain dedicated computing resources, either physically or logically separated, for all administrative tasks or tasks requiring administrative access. The computing resources should be segmented from the enterprise's primary network and not be allowed internet access.