What kind of vulnerability it may have for known ssh-hostkey?

I saw there is NSE script in nmap that can retrieve the ssh-hostkey(RSA or DSA) from the target host. For example,

22/tcp open  ssh
|  ssh-hostkey: 2048 f0:58:ce:f4:aa:a4:59:1c:8e:dd:4d:07:44:c8:25:11 (RSA)

Can anyone explain what could happen if we can get ssh-hostkey? Is it a kind of misconfiguration for ssh? Thanks.