Thanks for the A2A
This is a bit difficult question, difficult in the sense that different CS domains require you master different areas of mathematics, there is no well defined boundary for this and neither there will ever be since the field of Computer Science is still emerging and new fields of Research shows the application of mathematical in different dimensions.
Even so there are some topics which should be learnt well. They have been categorized under the named of Discrete Mathematics or Mathematics for Computer Science.
Topics which you should know :-
1. Set Theory (falls under Abstract Alg.) [Very Very Important]
2. Probability [Very Very Important]
3. Graph Theory [Very Very Very Important]
4. Abstract Algebra [Ring, fields, Sets]
5. Number Theory [Very Important]
6. Convex Optimizations [Important from Research Prospective]
7. Statistics [Important from Research Prospective]
8. Propositional Logic and Proofs.
9. Counting or Permutations and Combination
10. Linear Algebra and Some trigonometry [Required for Computer Graphics or GameDev]