CVE-2026-102139: Accellion Kiteworks

Medium severity, CVSS 6.5. EPSS: 0.4% chance of exploitation in the next 30 days.

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.

Affected products

• Accellion Kiteworks: before 9.5.1 (fixed in 9.5.1)

Published 2026-09-30. Last modified 2026-10-07.