[en] A measurement of the W boson pair production cross section in proton-proton collisions at √(s) = 8 TeV is presented. The data collected with the CMS detector at the LHC correspond to an integrated luminosity of 19.4 fb"-"1. The W"+W"- candidates are selected from events with two charged leptons, electrons or muons, and large missing transverse energy. The measured W"+W"- cross section is 60.1 ± 0.9 (stat) ± 3.2 (exp) ± 3.1 (theo) ± 1.6 (lumi)pb = 60.1 ± 4.8 pb, consistent with the standard model prediction. The W"+W"- cross sections are also measured in two different fiducial phase space regions. The normalized differential cross section is measured as a function of kinematic variables of the final-state charged leptons and compared with several perturbative QCD predictions. Limits on anomalous gauge couplings associated with dimension-six operators are also given in the framework of an effective field theory. The corresponding 95 % confidence level intervals are -5.7 < c_W_W_W/Λ"2 < 5.9 TeV"-"2, -11.4 < c_W/Λ"2 < 5.4TeV.2, -29.2 < c_B/Λ"2 < 23.9 TeV"-"2, in the HISZ basis. (orig.)