CVE-2026-102128

Kiteworks Email Protection Gateway rejected certain configuration settings, but its validation did not recognize every form in which they could be supplied. An authenticated administrator could potentially use an unrecognized form to have a file of their choosing written to the gateway and executed, resulting in code execution as the gateway service account.

Kiteworks Email Protection Gateway did not sufficiently validate the content of an uploaded backup, and allowed an administrator to influence how the application loaded it. An authenticated administrator could potentially use this to execute arbitrary code on the gateway as the underlying service account.

An XML parser used by Kiteworks Email Protection Gateway did not restrict external entity references. Where an optional, non-default message-processing feature is enabled, a remote and unauthenticated sender could potentially use a crafted message to read files accessible to the gateway service account, including cryptographic key material and credentials, and have them sent to a destination they control.

A weakness could allow an authenticated Kiteworks Email Protection Gateway administrator to write a file outside its intended location and cause the application to execute it, potentially resulting in remote code execution as the underlying service account.

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.

Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Remote Code Execution. The gateway allowed an authenticated administrator to import configuration whose contents were not sufficiently validated before being processed. A crafted submission could potentially allow arbitrary commands to be executed on the affected gateway.

Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to Unsafe Reflection and does not sufficiently restrict the code that the mail-processing pipeline could load from an imported rule configuration. An authenticated administrator with mail-rule configuration privileges could cause the gateway to load and execute code beyond the approved set of mail-processing components, potentially in the context of the mail-gateway service account.

Kiteworks Email Protection Gateway before version 9.5.0 is vulnerable to a path traversal weakness in an administrative import function allowed an authenticated administrator to write files to arbitrary locations on the server. This could potentially be leveraged to execute arbitrary code on the underlying system.

Kiteworks Email Protection Gateway did not sufficiently restrict which account a certificate could be assigned to. This could allow an attacker to associate a certificate with another user's account, affecting the confidentiality and integrity of that account's encrypted mail and, where certificate-based login is enabled, potentially permitting unauthorized access to the account.

Improper authentication in a Kiteworks Email Protection Gateway administrative service. An administrative service in Kiteworks Email Protection Gateway did not consistently enforce administrator authentication, so the required password check could be bypassed. An attacker who referenced a valid administrator account could potentially create, modify, or delete internal users and managed domains and change their security-feature configuration without authenticating; deleting a managed domain also removes its user accounts and could lock administrators out of the gateway.