Post-authentication remote command injection vulnerability in Western Digital My Cloud OS 5 devices that could allow an attacker to execute code in the context of the root user on vulnerable CGI files. This vulnerability can only be exploited over the network and the attacker must already have admin/root privileges to carry out the exploit. An authentication bypass is required for this exploit, thereby making it more complex. The attack may not require user interaction. Since an attacker must already be authenticated, the confidentiality impact is low while the integrity and availability impact is high.  This issue affects My Cloud OS 5 devices: before 5.26.300.