Last Modified: Jun 13, 2026
Affected Product(s):
BIG-IP LTM
Fixed In:
17.5.1.6, 17.1.3.2
Opened: Jan 19, 2026 Severity: 3-Major
When the `systemauth.primaryadminuser` value is changed to a non-existing user, the primary admin value is updated to the non-existing user, resulting in an admin user lockout scenario.
-- The admin user becomes disabled, logged out of TMUI and TMSH, and is unable to log back in. -- If the root account login is also disabled, both the root and admin users are logged out of the system.
When a user does not existing in the system and primary admin value is changed to non existing user value.
None
When the primary admin DB is udated below operations takes place; in case of failure to update sys db these will get rollbacked. -> Writes localusers file -> Writes URP file -> Clears PAM cache -> Writes f5_public file