Vinicius contract expires in 2027, but I think Real Madrid will try to keep him at the club for longer by offering him a new deal.
The only way to convince him to stay longer seems to give him what he wants:
• Equal salary with Mbappe's
Will they do this? I don't think so even a bit. Mbappe's salary goes up to €70m per year with bonuses. Vini makes €25m in total per year. There is a huuuge gap...
No doubt Vinicius Junior loves Real Madrid, and he wants to stay at Real Madrid for a long time, but since there is a huge gap between Vinicius Junior's and Mbappe's annual salaries, that will make Vinicius Junior demand an increment in his annual salary for him to renew his contract. If Real Madrid refuses to meet Vinicius Junior's demand, he will leave Real Madrid to join a club that will pay him what he wants.