I am not sure if this behavior is expected feature or if it is a regression but it is definitely confusing.

What were you trying to do that didn't work?

1. prepare test data
   [karel@testvm ~]$ mkdir -p A/B/C
   [karel@testvm ~]$ touch A/B/C/boom
   [karel@testvm C]$ mkdir ~/DEST
   [karel@testvm ~]$ cd A/B/C
   [karel@testvm C]$ ls ../..
   B

1. try to copy B to ~/DEST
   [karel@testvm C]$ scp -r ../.. karel@localhost:~/DEST
   karel@localhost's password:
   boom 100% 0 0.0KB/s 00:00

1. nothing there
   [karel@testvm C]$ ls ~/DEST/

1. B has been stored in ~ instead
   [karel@testvm C]$ ls ~
   A B DEST
   [karel@testvm C]$ find / -name boom 2> /dev/null
   /home/karel/A/B/C/boom
   /home/karel/B/C/boom

1. similar scenario with ..
   [karel@testvm C]$ cd ~/A/B
   [karel@testvm B]$ ls
   C
   [karel@testvm B]$ scp -r .. karel@localhost:~
   karel@localhost's password:
   scp: stat remote: No such file or directory
   scp: remote setstat "/home": Permission denied
   scp: failed to upload directory .. to ~

we can see that scp doesn't expact .. or ../.. to proper directory names

on RHEL-8 with openssh-8.0p1-25.el8_10.x86_64 this is not happening:

1. scp -r ../.. karel@localhost:~/DEST
   karel@localhost's password:
   scp: error: unexpected filename: ..

same behavir as on RHEL-8 is on RHEL-7 with openssh-7.4p1-23.el7_9.x86_64

What is the impact of this issue to you?

data are copied to an unexpected location

Please provide the package NVR for which the bug is seen:

openssh-9.9p1-13.el10.x86_64
openssh-9.9p1-7.el10_0.x86_64
also with
openssh-8.7p1-46.el9.x86_64

How reproducible is this bug?:

always

Steps to reproduce

above