Heat oil in large saucepan over medium-high heat. Cook and stir onion, jalapeno peppers, and garlic in the hot oil until the onion is tender, 5 to 7 minutes; season with cumin and cayenne pepper. Add corn, chicken broth, and diced chicken.
Bring the soup to a boil. Reduce heat to low, place a cover on the saucepan, and cook at a simmer until the chicken is cooked through, about 15 minutes. Remove saucepan from heat and let soup cool.
Pour soup into a blender no more than half full. Cover and hold lid down; pulse a few times before leaving on to blend. Puree in batches until smooth. Return pureed soup to the saucepan.
Place saucepan over low heat; warm soup, stirring occasionally, until hot, about 5 minutes. Garnish servings with lime wedges, cilantro, and sour cream.