WordPress 4.8.2 became available today. This is a security release for all previous versions, and you need to update your websites immediately. The update fixes 9 security issues.
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.