Short answer
A single small lick is unlikely to cause serious harm, but hummus is not cat food. The garlic and lemon juice in typical recipes are irritants and can cause mild stomach upset. The main risk at gatherings is that pets often find more than one forbidden snack. Remove your cat from the food area and offer fresh water. Watch for any vomiting, drooling, or diarrhea over the next several hours, and call your own vet if you notice anything concerning.
Hummus — Food safety facts
Feed with care · Cats · full breakdown on the linked food page
Chickpeas are fine but hummus brings garlic, lemon and tahini. Small taste only.
The full verdict, portion guidance and serving notes are collected on the Hummus food facts page.