On November 28, 2017, Microsoft released SQL Server 2017 CU2, which is build 14.0.3008.27. I count 33 hotfixes in this CU. What is interesting is that there is a new column in the fix list called Platform, which will have a value of All, Linux, or Windows to indicate which platform the fix is relevant for. There are six Linux-only fixes, ten Windows-only fixes, with the remaining 17 fixes being for all platforms (Linux and Windows).
Keep in mind that with the Modern Servicing Model (MSM) that will be used for SQL Server 2017, there will be no Service Packs, and there will be monthly Cumulative Updates for the first twelve months after GA. After the first twelve months, there will be quarterly CUs for the next four years.
Microsoft has also changed their previous commitment to release CUs during the week of the 3rd Tuesday of the month of release. Going forward, they will just be released sometime during the month. This is fine with me, since I would rather see a solid release rather than one rushed out the door to hit a specific week of the month.
In my experience, checking the SQL Server 2017 build versions page is the best way to find out when a new CU has been released. You can also just follow me on Twitter, since I always tweet a link when a new CU is released.