zsh through version 5.4.2 is vulnerable to a stack-based buffer overflow in the exec.c:hashcmd() function. A local attacker could exploit this to cause a denial of service.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:H5.5/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HOther