oscap-ssh: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/oscap-ssh - from package: openscap-utils

You may install the required package with command yum install {package}

Error in other languages:
oscap-ssh: bevel nie gevind nie
oscap-ssh: comandă negăsită
oscap-ssh: comando não encontrado
oscap-ssh: commande introuvable
oscap-ssh: command not found
oscap-ssh: käsku ei ole
oscap-ssh: không tìm thấy lệnh
oscap-ssh: komanda nerasta
oscap-ssh: Kommando nicht gefunden.
oscap-ssh: kommandot finns inte
oscap-ssh: komut yok
oscap-ssh: nie znaleziono polecenia
oscap-ssh: níor aimsíodh an t-ordú
oscap-ssh: no se encontró la orden
oscap-ssh: no s'ha trobat l'ordre
oscap-ssh: opdracht niet gevonden
oscap-ssh: parancs nem található
oscap-ssh: perintah tidak ditemukan
oscap-ssh: príkaz nenájdený
oscap-ssh: příkaz nenalezen
oscap-ssh: команда не найдена
oscap-ssh: командата не е открита
oscap-ssh: 命令找不到
oscap-ssh: コマンドが見つかりません