  We investigate the constrained Minimal Supersymmetric Standard Model (cMSSM)
in the light of constraining experimental and observational data from precision
measurements, astrophysics, direct supersymmetry searches at the LHC and
measurements of the properties of the Higgs boson, by means of a global fit
using the program Fittino. As in previous studies, we find rather poor
agreement of the best fit point with the global data. We also investigate the
stability of the electro-weak vacuum in the preferred region of parameter space
around the best fit point. We find that the vacuum is metastable, with a
lifetime significantly longer than the age of the Universe. For the first time
in a global fit of supersymmetry, we employ a consistent methodology to
evaluate the goodness-of-fit of the cMSSM in a frequentist approach by deriving
p-values from large sets of toy experiments. We analyse analytically and
quantitatively the impact of the choice of the observable set on the p-value,
and in particular its dilution when confronting the model with a large number
of barely constraining measurements. Finally, for the preferred sets of
observables, we obtain p-values for the cMSSM below 10%, i.e. we exclude the
cMSSM as a model at the 90% confidence level.
