Unchecked NULL pointer usage in xkbcommon before 0.8.1 could be used by local attackers to crash (NULL pointer dereference) the xkbcommon parser by supplying a crafted keymap file, because geometry tokens were desupported incorrectly.
https://access.redhat.com/errata/RHSA-2019:2079
https://github.com/xkbcommon/libxkbcommon/commit/e3cacae7b1bfda0d839c280494f23284a1187adf
https://lists.freedesktop.org/archives/wayland-devel/2018-August/039232.html
https://security.gentoo.org/glsa/201810-05