Accellion FTP server prior to version FTA_9_12_220 only returns the username in the server response if the username is invalid. An attacker may use this information to determine valid user accounts and enumerate them.
Severity
CVSS 3.0
5.3 medium
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
EPSS
7.7% chance of exploitation in the next 30 days; higher than 94% of CVEs (scores of 2026-10-31)