Nokia Mobile has a reputation in delivering updates across their whole lineup. One of the latest devices that started receiving the latest security patch are the Nokia 3.1 Plus and Nokia 5.1 Plus.
The update for Nokia 5.1 Plus contains just the security patch for October 2019 and is around 73MB in size. The update is also rolling out for Nokia 3.1 Plus, according to Piunikaweb.
To check if the update is available for your device head to Settings->System->System update.