Bed rust, 2002 Tacoma

I’ve got some rust in the wheel well area of the bed. It’s right on the corner seam and the worst part is about 3 inches wide. It is rusted through to the bed liner. There is surface rust about 2 inches further down along the seam as well, but it is not rusted through yet. On a scale of 1-10 how much of an issue is this and how concerned should I be about how much weight I haul in the bed with rust like this?

 

That shouldnt affect the capacity
The load is supported on the crossbar you see in the picture

 

you mean the capacity is put on the crossbar that is also rusted and where the bed meets that crossbar is essentially rusted out?

Not saying your overall capacity has changed but that spot is most definitely weakened. Get some POR15 to put on it right away to convert the rust and stop further deterioration. But seeing as ahead the wheel well/bed is separating at the layers, I would personally look at taking the bed off the truck and flipping it over to confirm the supports and structure of the bed isnt compromised where you cant see.