Atomic-sizes’ misfit and elastic-moduli misfit for the solute atoms at the crystal-lattice sites in concentrated solid solution, notably, in multicomponent alloy, can be considered as discrete random variables. Definition of variance of such random variables allows to develop method and analytical expressions to determine the main parameters of stochastic shearing-stresses’ field that is generated within the glide plane by solute atoms. The main parameters are the standard deviations and correlation lengths of the short- and long-wavelength components of this field. The developed method also shows that it is possible to determine two different effective distortions of crystal lattice, each of which is responsible for its own component of the shearing-stresses’ field. Another conclusion of the new method is that there is no single empirical constant for all alloys at once to determine the yield strength using the shear modulus and average lattice distortion. The short-wavelength component of the shearing-stresses’ field within the glide plane creates dominant force barriers, which the dislocation can overcome by the thermal-activation assistance. The long-wavelength component creates barriers, which can be overcome athermally, that is, by applying additional mechanical stress. All these barriers can be described using the main parameters of the shearing-stresses’ field. Effect of solute atoms located farther from the glide plane on yield strength cannot be neglected because they create long-wavelength component of the shearing-stresses’ field. The analysis of overcoming barriers from the short- and long-wavelength components of the shearing-stresses’ field is resulted in describing the temperature dependence of the yield strength of a multicomponent alloy. This dependence describes well the mechanical behaviour of the alloy in a wide range of temperatures, including in the range of the high-temperature ‘plateau’, except very low and very high temperatures, where additional factors and mechanisms operate.