Latest secure kernels available in the repos for 32 and 64 bit architecture (stretch, buster, testing and sid).
5.2.8 (64bit and 32 bit pae and non-pae-486)
4.19.66 (64bit and 32 bit pae and non-pae-486)
4.9.189 (64 bit and 32 bit pae and non-pae-486)
Users are strongly advised to upgrade.