In the following, Josephus seems to indicate that others besides Noah and his family survived the flood:
Now, the sons of Noah
were three--Shem, Japheth, and Ham, born one hundred years before the Deluge.
These first of all descended from the mountains into the plains, and fixed
their habitation there; and persuaded others (τοὺς ἄλλους) who were
greatly afraid of the lower grounds, on account of the flood, and so were very
loath to come down from the higher places, to venture to follow their examples.
(Antiquities of the Jews 1.109)