Do electrons interact attractively?

I read that electrons could interact attractively in superconductors and form Cooper pairs. This attraction is due to the electron–phonon interaction, with the phonon being the collective motion of the positively charged lattice. Electrons could also interact attractively through Z-boson exchange at short-ranges, but sadly weak nuclear forces are weaker than electromagnetic forces. So, theoretically, are there any bosons (integer-spin particles or composed systems) that could induce stronger-than-electromagnetic attractive forces between electrons?