Stellar evolution is a well advanced study. The sun is a yellow dwarf and about half-way through its life cycle. It should be stable, as you see it today, for billions of years into the future.
However, this does not mean that it will not explode in December.
It simply cannot be ruled out that some alien species has planted a sophisticated mechanism in the center of the sun, and this is set to go off in December. The chances of this however are extremely remote - fanciful at best. You would be better off buying lottery tickets in December than worrying about the sun exploding. The lotto offers much better chances.
January is another story. The aliens may have miscalculated and detonation could be delayed by a month or so. If you happen to win the lotto, and if you are still really concerned about the sun exploding, you might consider spending your winnings quickly, perhaps all in one place.......