CVE-2023-40044: Progress WS_FTP Server Deserialization of Untrusted Data Vulnerability

High severity, CVSS 8.8. Actively exploited: in CISA KEV since 2023-10-05. EPSS: 90.4% chance of exploitation in the next 30 days.

In WS_FTP Server versions prior to 8.7.4 and 8.8.2, a pre-authenticated attacker could leverage a .NET deserialization vulnerability in the Ad Hoc Transfer module to execute remote commands on the underlying WS_FTP Server operating system.

Affected products

• Progress WS_FTP Server: before 8.7.4 (fixed in 8.7.4); from 8.8, before 8.8.2 (fixed in 8.8.2)

Published 2023-09-27. Last modified 2026-06-17.