Here's the complete process I followed:
1. Search for "windows smb server vuln" in Google.
2. "Microsoft Security Bulletin MS17-010 - Critical"[0] is the link I'm looking for.
3. Search for your version in the list. Mine is "Windows 10 Version 1607", listed in the table with 4013429 (right next to the Windows version, not in "Updates replaced"). That's my update number.
[0] https://technet.microsoft.com/en-us/library/security/ms17-01...