There are still existing vulnerabilities in gambling websites till this day, but I believe they are not as notorious like before and many are just seldom occurring and are workable to be fixed immediately. Although, one thing I observed to be happening frequently than the others is the issues with regards to the security and such, and like what @ayuskabob said, it is majorly the new ones. Maybe this is also in the question of the capacity of the team to acquire such resources and services that could help them fill these vulnerabilities.