[_Lemon_]

I have a response from OVH:

We are aware of this and are currently investigating it. Our initial thoughts were that it was indeed a compromise but after further review it seems that this is actually a bug with Debian and certain versions of RedHat.

We've tested it with different keys and have suffered the same results. I'll let you know if anything changes and we'll be announcing this shortly.

Thank you in any case, but rest assured it's not a serious issue.