3 Seemingly Identical SMBv1 CVEs

Why are there 3 seemingly identical CVE’s for SMBv1 vulnerability? What’s the difference between them? CVE-2017-0277, CVE-2017-0278, CVE-2017-0279.

 

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0277

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0278

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0279