Last Modified: Aug 25, 2026
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
21.1.0
Fixed In:
21.1.0.1
Opened: Apr 15, 2026 Severity: 2-Critical
TMM experiences crashes on certain platforms when the PQC DH group is utilized
Service availability
Enable the DH group X25519MLKEM768 on platforms that do not support the CPU feature AVX2 This may rarely include CPUs used on hypervisor systems, but more often will be due to virtualisation software not exposing the AVX2 feature set to the guest vCPUs. F5 r2xx and r4xx lack AVX2.
If AVX2 instruction family is not exposed to guest then this might be a configuration issue on hypervisor, if hypervisor host CPU has the feature. On ESXi, for example, guest virtual machine type 13 (compatibility with ESXi 6.5) and above for would be needed to expose AVX2 on guest vCPU. If AVX2 not present then disable PQC DH group on BIG-IP.
TMM uses software alternative when AVX2 instruction is not available.