CVE-2026-28272 is a stored cross-site scripting (XSS) vulnerability classified under CWE-79 affecting the Kiteworks Email Protection Gateway prior to version 9.2.0. The vulnerability arises from improper neutralization of input during web page generation in the administrative configuration interface. Specifically, authenticated administrators can inject malicious JavaScript code into configuration fields that are stored and later rendered in the user interface without proper sanitization or encoding. When other users interact with the affected UI components, the malicious script executes in their browsers within the security context of the Kiteworks application. This can lead to session hijacking, credential theft, unauthorized actions, or further exploitation within the private data network. The vulnerability has a CVSS 3.1 base score of 8.1, reflecting its high impact on confidentiality and integrity, with network attack vector, low attack complexity, and requiring high privileges and user interaction. The scope is changed (S:C) indicating that the vulnerability affects resources beyond the initially vulnerable component. Kiteworks addressed this issue in version 9.2.0 by implementing proper input validation and output encoding to neutralize malicious scripts. No public exploits have been reported to date, but the vulnerability poses a significant risk due to the sensitive nature of the platform and the administrative access required to exploit it.

The impact of CVE-2026-28272 is significant for organizations using Kiteworks Email Protection Gateway versions prior to 9.2.0. Successful exploitation allows an authenticated administrator to inject malicious scripts that execute in other users' browsers, potentially leading to session hijacking, theft of sensitive data, unauthorized configuration changes, or lateral movement within the private data network. Given Kiteworks' role in secure data exchange and email protection, compromise could expose confidential communications and sensitive organizational data. The requirement for administrator privileges limits the attack surface but insider threats or compromised admin accounts increase risk. The vulnerability affects confidentiality and integrity severely, though availability impact is minimal. Organizations relying on Kiteworks for secure data handling could face regulatory compliance issues, reputational damage, and operational disruptions if exploited.

To mitigate CVE-2026-28272, organizations should immediately upgrade Kiteworks Email Protection Gateway to version 9.2.0 or later, where the vulnerability is patched. Additionally, restrict administrative access strictly using the principle of least privilege and enforce strong authentication mechanisms such as multi-factor authentication (MFA) for all admin accounts to reduce the risk of credential compromise. Conduct regular audits of administrator activities and configuration changes to detect suspicious behavior. Implement Content Security Policy (CSP) headers to limit the impact of potential XSS attacks by restricting script execution sources. Educate administrators on secure input handling and the risks of injecting untrusted content. Finally, monitor logs and network traffic for unusual activity that could indicate exploitation attempts. Avoid using vulnerable versions in production environments until patched.