Life in temperatures that melts lead? Oh... or do you mean in the atmosphere?
For all we know the Soviet Vega missions could have introduced airborne microbial life into the high atmosphere. We may have already seeded Venus.
Either. It does seem unlikely, but the truth is we just don't know.
> Life in temperatures that melts lead?
Why not? It'd have to have different chemistry, sure, but even on Earth life exists in some pretty extreme temperature and environment ranges.
Life really starts to struggle above 100 C. I think the most heat tolerant organisms we know of top out around 130 C.
Life that could operate at 500 C is probably not water based at all, which would be very novel and certainly interesting to science.
It seems like a remote risk to me, but not something to shrug off. Particularly since the usefulness of introducing life to Venus is itself quite remote.