The official Security+OS update tracker page for Nokia smartphones has been updated on December 30 by Nokia Mobile (HMD) with details about the availability of December Security updates for all Nokia smartphones. As you may be already aware the page lists Build number and details like whether it is just a security patch or firmware update + security patch for a particular device.
As per the latest updated information provided on the page, currently, December Security update is available for many of the Nokia smartphones, though many others including Nokia 6.1 Plus, Nokia 1 Plus, Nokia 7 Plus are yet to receive the December patch.
In case the security update is not yet available for your Nokia smartphone, you should check the build number of your smartphone and confirm it with the information provided on the page. If the build number for a particular device is mentioned in the list then only it gets the update.
HMD earlier announced the extension of Android security updates support for its very first batch of smartphones Nokia 3, 5, 6 and 8. But the security update roll-out will switch to quarterly until 2020 for these smartphones.
You can also click here for our detailed coverage of all software update news related to Nokia smartphones.