---
id: CVE-2026-102139
title: >-
  An authorization check in the large file exchange feature of Kiteworks Email
  Protection Gateway did not correctly establish that the requesting user was a
  party to the package being requested
summary: >-
  An authorization check in the large file exchange feature of Kiteworks Email
  Protection Gateway did not correctly establish that the requesting user was a
  party to the package being requested. An authenticated user of that optional
  featu…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-639
  - CWE-863
vendor: Kiteworks
product: Email Protection Gateway
affected:
  - email_protection_gateway < 9.5.1
published: '2026-09-30'
updated: '2026-09-30'
sourceUpdated: '2026-09-30T21:17:02.663'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-102139'
references:
  - url: >-
      https://github.com/kiteworks/security-advisories/security/advisories/GHSA-fp46-xhg8-vpgm
    label: 9119a7d8-5eab-497f-8521-727c672e3725
  - url: >-
      https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/VA/white/2026/va-26-274-01.json
    label: 9119a7d8-5eab-497f-8521-727c672e3725
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-30T21:25:07.835Z'
---

## Overview

An authorization check in the large file exchange feature of Kiteworks Email Protection Gateway did not correctly establish that the requesting user was a party to the package being requested. An authenticated user of that optional feature could read the subject, message body, and attachments of packages they neither sent nor received.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.