Greg Kroah-Hartman has released the 5.8.1, 5.7.15, 5.4.58, and 4.19.139 stable kernels. As usual, these contain lots of important fixes throughout the tree; users should upgrade.

Source: LWN.net – Stable kernels 5.8.1, 5.7.15, 5.4.58, and 4.19.139