Yeah they look rather sickly. Why don't you put them in the ground. Pumpkins aren't the best pot plants, they do much better transplanted s soon as possible.

I have a similar looking problem that's also affecting spinach and lettuce. they're in a raised bed. I have tried ground eggs shells, beer traps, flat boards (to attract earwigs) and a few different, pet-safe spray remedies. I've even checked with a flashlight at night. I simply cannot find any sign of what might be causing this damage!! Tomatoes are thriving right next to these plants with no adverse effects. Help, please!

i had the exact same thing, i covered my garden with pollen plants to attract insects like ladybugs and hoverflies to eat any bad bugs and also distraction plants such as marigold. i sprayed with pesticides as well- im sorry to say im not sure which one worked! i done all three within a matter of a week in a moment of panic but my pumpkins are now growing really well with no sign of brown or dying leaves.

i should add that this happened when they were in the ground but they look a lot healthier!

Have you inspected the underside of your leaves? Aphid damage looks somewhat similar to this and they like to hang out on the underside of leaves. Do you have an extension office nearby? If so call your horticulture specialist and see what he/she recommends. :) Good luck!