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 security@lightning.engineering (this list isn't to be used for support).
The following key can be used to communicate sensitive information: 91FE 464C D751 01DA 6B6B AB60 555C 6465 E5BC B3AF
.