The package handlebars before 4.7.7 are vulnerable to Prototype Pollution when selecting certain compiling options to compile templates coming from an untrusted source.
https://security.netapp.com/advisory/ntap-20210618-0007/
https://github.com/handlebars-lang/handlebars.js/commit/f0589701698268578199be25285b2ebea1c1e427