On 10–15 June, Mamun competed at the 2014 European Championships and finished 5th in all-around after a mistake ridden hoop routine and 3 drops in her clubs routine. Mamun returned to competition in August and took the silver medal in all-around at the 2014 Sofia World Cup, she qualified to 2 event finals and won silver in ball and clubs. On 5–7 September, competing at the 2014 World Cup series in Kazan, Mamun took the all-around silver medal behind Kudryavtseva with a total of 73.250 points. She qualified to 3 event finals and won gold in hoop, silver in ball and placed 4th in ribbon.