Within the Constrained Minimal Supersymmetric Standard Model (CMSSM) with Minimal Flavor Violation (MFV) for scalar quarks, we study numerically the effects of intergenerational squark mixing on B-physics observables, electroweak precision observables (EWPO), and the Higgs-boson mass predictions. In models with universal soft terms at the GUT scale, squark mixing is generated through the Renormalization Group Equations (RGEs) running from the GUT scale to the electroweak scale due to presence of non-diagonal Yukawa matrices in the RGEs, e.g. due to the CKM matrix. Our numerical analysis is based on the code Spheno for the RGE running and full one-loop calculations, supplemented by further higher-order corrections, at the electroweak scale of the precision observables as included in the code FeynHiggs. Taking the CMSSM as a concrete "realistic" example, we find that the B-physics observables as well as the Higgs mass predictions do not receive sizable corrections. On the other hand, in our numerical analysis we observe that the EWPO such as the W boson mass can receive relevant corrections. Such contributions could in principle be used to place new bounds on the CMSSM parameter space. We extend our numerical analysis to the CMSSM extended with a mechanism to explain neutrino masses (CMSSMseesaw I), which induces flavor violation in the scalar lepton sector. The effects of slepton mixing on the analyzed observables are found to be, in general, smaller than those of squark mixing, but in our numerical analysis reach the level of the current experimental uncertainty for the EWPO.M. Rehman is a MulitDark Scholar. a