Last Modified: May 07, 2026
Affected Product(s):
BIG-IP TMOS
Fixed In:
17.5.1.6, 17.1.3.2
Opened: Dec 29, 2025 Severity: 2-Critical
TMM crashes and restarts.
Traffic disrupted while tmm restarts.
In an F5OS multi-slot tenant environment, during boot-up after a tmsh reboot slot all or upgrading to a new volume, a switch of the primary slot can occur between the slots due to slot readiness states. If tmm sends a shared_random_data message before receiving the updated primary slot ID from mcpd, it might use the previous primary slot ID, resulting in a data mismatch and causing tmm to crash and restart. Note: This issue occurs very rarely as it depends on a race condition.
None.
The issue has been fixed by skipping the setting of shared random data when this race condition occurs. The operation will be retried after TMM receives the primary slot change notification.