In params.c in zsh through 5.4.2, there is a crash during a copy of an empty hash table, as demonstrated by typeset -p.
{
"availability": "No subscription required",
"binaries": [
{
"binary_version": "5.0.2-3ubuntu6.1",
"binary_name": "zsh"
},
{
"binary_version": "5.0.2-3ubuntu6.1",
"binary_name": "zsh-beta"
},
{
"binary_version": "5.0.2-3ubuntu6.1",
"binary_name": "zsh-common"
},
{
"binary_version": "5.0.2-3ubuntu6.1",
"binary_name": "zsh-static"
}
]
}