As of November 2016, the Security Bulletins index
runs for a daunting 57 pages, with a list of updates that goes back to 2008. Each individual bulletin in turn includes details about that patch for each software package it affects, with links to Knowledge Base numbers that in turn contain additional details.
It's a rabbit hole that even security experts can quickly get lost in, and the entire concept of an index page of static documents is increasingly old-fashioned.
So, beginning in early 2017, Microsoft says
it will scrap that entire system in favor of a new "single destination for security vulnerability information" called the Security Updates Guide
The new security portal
is driven by an online database. Instead of having to poke through an index of documents, you can sort, search, and filter the database to find details about a specific security bulletin and its associated updates.