> during or after a TLS 1.3 handshake
Sure, openSSL is not SSH, but it is not unreasonable to assume this leak may affect web servers as well (e.g. by being based on the same underlying TLS implementation).
"SSH != SSL" is a bit short to invalidate the assumption of the OP. I'd not be so sure this problem does not affect "web server X".
https://en.wikipedia.org/wiki/Transport_Layer_Security
OK, learnt something new today: https://crypto.stackexchange.com/questions/60255/why-doesnt-...
Thanks! :)