I wonder if SQL Server CUs contain lower Service Packs. I am asking this because I have a SQL Server 2014 which was patched automatically with CU7 and later that week someone applied Service Pack 2 and a bug that was fixed started appearing again, this bug was fixed on CU3 BTW. For what I saw SP2 was released before CU3 and CU7 but since it was installed later seems that it overwrote the bug fix, even though the SQL Server build number was 12.2.5556.0, it did not contain the fix.
In the end I installed latest CU (CU8) and it was fixed again, but I wonder why it did not detect that CU was ahead of the SP?
Here is the sequence of installation:
It was confirmed on the Windows Update History: