Latest secure kernels available in the repos for 32 (pae and non-pae) and 64 bit architecture.
5.5.0 (antiX-17, antiX-19, testing and sid)
4.19.100 (antiX-17, antiX-19, testing and sid)
4.9.212 (antiX-17, antiX-19, testing and sid)
4.4.212 (antiX-16, antiX-17, antiX-19)
Note: The 5.5.0 kernel will not build broadcom-sta wifi, nvidia drivers or virtualbox drivers (yet).