A very common challenge, easily dealt with
When I worked with Lencarta I designed a range of pro softboxes, they had a D-ring sewn into each corner, like this one
View attachment 475070
Sadly, most people now go for the cheapest softboxes and I think that this pro range was discontinued, but we can sew on D-rings ourselves. Just use them to secure the softbox to a tree, a vehicle, to tent pegs hammered into the ground, whatever's there, using nylon paracord, very thin and lightweight, but very strong. And of course, we can secure the flash head and the stand in the same way, we can also hang weights from the stand, but the D-rings work best of all.
And remember, the bigger the sail, the more dramatic the fail
The old video below was made well before we added the D-rings, the shoot took place in good weather without a wind problem, even so I tied gear down, more out of habit than actual need, and you can see this at 1 minute 44, with just the stand tied down - there may be other examples in that video, I haven't checked.
Incidentally, the bunch of
reprobates incredible photographers in the background were all forum members, I used to invite people along to shoots sometimes.