Last Modified: Apr 09, 2026
Affected Product(s):
F5OS Install/Upgrade, Velos
Known Affected Versions:
F5OS-A 1.8.0, F5OS-A 1.8.1, F5OS-A 1.8.2, F5OS-A 1.8.3, F5OS-C 1.8.0, F5OS-C 1.8.1, F5OS-C 1.8.2
Opened: Oct 21, 2025 Severity: 3-Major
TCP packets (e.g., ServerHello) are dropped between F5OS and tenant, causing application slowness or outages when connections exceed ~25K.
- -Application downtime or degraded performance -- Service disruption at high connection counts
-- F5OS-A upgraded to 1.8.3 (from 1.3.2) -- BIG-IP tenant running 17.1.3 or 17.5.1 -- TCP ACK (TS) DoS vector enabled (default or low threshold settings) -- High connection rates (25K–30K+ active connections)
Raise TCP ACK (TS) vector thresholds per K000139860 Disable the vector if not needed
None