how's their update schedule for Security fixes and OS versions? How botched are their security lockdown of their phones compared to the Nexus line? Can't seem

how's their update schedule for Security fixes and OS versions? How botched are their security lockdown of their phones compared to the Nexus line? Can't seem to find a list of CVE's fixed with each update (not in their changelogs, that they only post on the forum...) , based on that, they do not fix known security problems.