commented:
Same issue.. observing it for last 4 hours.
It is already mentioned on
https://www.githubstatus.com/incidents/g40zcbvchny4

  commented:
I had an issue just a few weeks ago where I rotated some SSH keys, but
I didn't remove the existing .pub files which were ignored in Git. I
tried to SSH in with these new keys but they just would not work. I
eventually enabled a bunch of debug flags and it took me a long time
to realise that my SSH client was sending the old fingerprint. I had
no idea OpenSSH read .pub files at all - all these years I've just
assumed they're completely redundant.

  commented:
We just faced the same issue today. There's no announcement from
GitHub, as far as I know, that they planned to change their SSH
authorization behavior.

  commented:
I don't expect that they planned it.

  commented:
I don't expect they plan most things they do currently

  commented:
What do you mean? I'm sure they typed /plan into Claude before they
wrote the code, almost half the time!

  commented:
Thank you! I'd just started looking at this when I saw the post pop up
in #lobsters, you saved me so much time.

  commented:
I had this issue today as well! Our CI server could seemingly no
longer connect to github.com.
Ended up rotating the key to a proper ed25519 key and it worked again.
This key still does not have a companion .pub key so i have no clue
why this worked

  commented:
Trick with ed25519 does work too

  commented:
I was mostly concerned about some sort of compromise when my key
stopped working out of the blue... good thing GitHub themselves seem
to be on it now.

  commented:
I had a issue where I lost my password and didn't have my recovery
keys. I was put through some account recovery process that used my ssh
key. GitHub had also decided that my ssh key "expired" and so I lost
access to my account entirely.

  commented:
Wow, I don't think i have had a .pub file in 7-8 years, i hope it's
fixed before i need to use github at some point

  commented:
If "both flows are legal", why does the probing flow exist at all?
Doesn't that just invite this kind of weirdness? Or, since you can
generate a public kry from the private key anyway, why doesn't ssh do
this automatically?

  commented:
Interestingly, my work Office 365 account unexpectedly stopped working
today, for the first time in 5 years.
Maybe something got compromised at Microsoft and they had to re-salt
everything again? Or maybe it’s only for Europeans, because of the
recent Chat Control 1.0 vote?
.