Spectre SWAPGS gadget vulnerability (CVE-2019-1125) allows an unprivileged local attacker to bypass conventional memory security restrictions to gain read access to privileged memory that would otherwise be inaccessible.

At the bottom i present the kernel versions with mitigations for the above vulnerability:

4.4 >=sys-kernel/gentoo-sources-4.4.188

4.9 >=sys-kernel/gentoo-sources-4.9.188

4.14 >=sys-kernel/gentoo-sources-4.9.188

4.19>=sys-kernel/gentoo-sources-4.19.65