The last major lnd release is to be considered the current support version. Given an issue severe enough, a backport will be issued either to the prior major release or the set of releases considered utilized enough.
To report security issues, send an email to loshan1212@gmail.com (this list isn't to be used for support).
The following key can be used to communicate sensitive information: c092 1846 fed0 bf4c f28b e1d7 3b2a 6315 cd51 a673.