As confirmed by HMD India in a community post, March Security update has now started rolling out to Nokia 5, 6 and 8. The update got delayed because of a one-time issue as per HMD India.
Nokia 5 March Security update is 267 MB in size, Nokia 8 update is 95 MB in size and Nokia 6 March Security update is 345 MB in size.
Nokia 5, 6 and 8 March Security update changelog:
The changelog mentions only the March Android Security update. It brings fix for many security issues. The most severe of these issues is a critical security vulnerability in Media framework that could enable a remote attacker using a specially crafted file to execute arbitrary code within the context of a privileged process.
HMD has been quite consistent in terms of releasing Monthly Security updates and OS updates for Nokia smartphones already available in the market. HMD has also made it clear that all Nokia Android Phones will receive minimum two years of OS update support.
Thanks iamshivaji_n, Jackson, Nuno, Shubham & others for the tip. Cheers!!