Dilepton production in pp and CC collisions with HADES

e + e − production was studied using the High Acceptance DiElectron Spectrometer (HADES). In pp collisions at 2.2 GeV kinetic beam energy, the exclusive η production and the Dalitz decay η → γe + e − have been reconstructed. The electromagnetic form factor of the latter decay was found to be in good agreement with the existing theoretical predictions. In addition, an inclusive e + e − invariant-mass spectrum from the 12C + 12C reaction at 2 AGeV is presented and compared with a simplified thermal model.