Scalar correlator at [symbol: see text](alpha(s)4), Higgs boson decay into bottom quarks, and bounds on the light-quark masses.

We compute, for the first time, the absorptive part of the massless correlator of two quark scalar currents in five loops. As physical applications, we consider the [symbol: see text](alpha(s)4) corrections to the decay rate of the standard model Higgs boson into quarks, as well as the constraints on the strange quark mass following from QCD sum rules.