VMware photon OS is described as “yum compatible.” Yum has been the package manager for all Fedora derivative distros like RHEL and CentOS. Photon OS actually uses Tiny DNF (TDNF), which appears to be a fork of the Fedora DNF package management system.
The fact that Photon OS is yum compatible is a tremendous improvement over many previous virtual appliance Operating Systems, because it gives end-users and developers alike an easy-to-use means of updating the appliance.
Anytime you read about shell vulnerabilities, or have other reasons to update, just run (as root):
The system will scan the configured repositories and prompt you to download any needed updates from the default repositories.
This is going to take some time, there’s more to download than the original ISO size!