  In this work, the mass of the strange quark is calculated from QCD sum rules
for the divergence of the strangeness-changing vector current. The
phenomenological scalar spectral function which enters the sum rule is
determined from our previous work on strangeness-changing scalar form factors
[1]. For the running strange mass in the MS_bar scheme, we find m_s(2 GeV) = 99
+- 16 MeV. Making use of this result and the light-quark mass ratios obtained
from chiral perturbation theory, we are also able to extract the masses of the
lighter quarks m_u and m_d. We then obtain m_u(2 GeV) = 2.9 +- 0.6 MeV and
m_d(2 GeV) = 5.2 +- 0.9 MeV. In addition, we present an updated value for the
light quark condensate.
