Improper privilege management in Serv-U FTP Server - CVE-2026-28306
Published: July 21, 2026 / Updated: July 27, 2026
Vulnerability identifier: #VU139686
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-28306
CWE-ID: CWE-269
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote user to escalate privileges.
The vulnerability exists due to improper access control in Serv-U when managing administrator roles. A remote user can elevate an existing account to escalate privileges.
This issue allows a domain administrator to elevate their privileges to a system administrator. The impact is lower in Windows deployments.
Affected software
Serv-U FTP Server
How to mitigate CVE-2026-28306
Install security update from vendor's website.
Serv-U FTP Server - update to 2026.3