Last Modified: Feb 15, 2026
Affected Product(s):
BIG-IP F5OS-C, TMOS, vCMP, Velos
Known Affected Versions:
17.5.1.3
Fixed In:
21.0.0, 17.5.1.4
Opened: Oct 10, 2025 Severity: 2-Critical
When a VIPRION vCMP guest or VELOS tenant is created with a management subnet mask other than a /24 (i.e. a /23 or a /25), the configured netmask is ignored and the system uses a /24 netmask.
The wrong subnet is assigned to the management IP address
-- Creating a VELOS tenant or VIPRION vCMP guest -- Assigning an explicit subnet as /23 or any subnet other than /24
None
The correct management netmask is used.