Normally, your #RaspiBlitz SSH is safe behind a home router NAT, but manual updating is recommended until a new RaspiBlitz release. On the terminal, type:
sudo apt-get update
sudo apt-get upgrade openssh-server
Discussion
Should be "install", not "upgrade", no?
I might jump in here.
sudo apt-get update
sudo apt-get upgrade openssh-server
as stated by nostr:nprofile1qqsdzexh3s943m0tyt25jskv7tup2kl053wupcm30nqls8g0zy69r0cpzemhxue69uhhyetvv9ujuurjd9kkzmpwdejhgqgjwaehxw309ac82unsd3jhqct89ejhxqg5waehxw309aex2mrp0yhxgctdw4eju6t07jl2uc is correct. The bug has been fixed in the latest Debian openssh-server package. Which means this package has to be upgraded.
(The first command "apt-get update" just fetches the newest package list).