WordPress 4.7.3 became available today. This is a security release for all previous versions and it’s strongly recommended to update your sites immediately. The new version addresses six security issues that may put your website at risk of being hacked.
While WordPress.org already started automatic background updates that do not require you to do anything it may take some time for them to get to your website. If it does not update automatically today, do it yourself (if you are confident enough) or contact Dusk Owl for help.