Baking at a lower temperature than the recipe calls for
Convert 350°F to 175°C - I don't think there's any lower temperature issue here.

If your oven goes up to 260 degrees, I'm guessing that's 260°C, not 260°F. (260°C is 500°F, so that's not a surprising maximum temperature to see, whereas a max of 260°F would be a pretty useless oven.)

A cake recipe that calls for 350 degrees is most likely 350°F, especially if you happen to know it's an American recipe. 350°F is an extremely common temperature in American recipes, possibly the most common. (A baking temperature of 350°C is really high and pretty unlikely - pretty much just for things like pizza, and certainly not cake.)