It is narrated from Hazrat Thawban (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Both the one who applies cupping and the one to whom it is applied, their fast is broken.
Hadith Referenceمسند احمد / مسند الأنصار رضي الله عنهم / 22429
Hadith Gradingحکم دارالسلام:حديث صحيح، وهذا إسناد ضعيف لضعف شهر