Yeah, you’re right. Every definition I can find for cunt is either vulva or vagina, but none say it refers to both. I think it’s just used interchangeably for both. I think the only term that refers to everything would be “female reproductive organs” and “female genitalia”, but that does include things like the uterus and the ovaries that both vulva and vagina (and therefore cunt), don’t include. I could certainly be wrong though.