Endless recursion exists in xkbcomp/expr.c in xkbcommon and libxkbcommon before 0.8.1, which could be used by local attackers to crash xkbcommon users by supplying a crafted keymap file that triggers boolean negation.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:H5.5/CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H