A study of excited ({\Lambda }{b}^{0}) baryons is reported, based on a data sample collected in 2016–2018 with the CMS detector at the LHC in proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of up to 140(\phantom{\rule{0.2em}{0ex}}{\text{fb}}^{-1}). The existence of four excited ({\Lambda }{b}^{0}) states: ({\Lambda }{b}^{0}{\left(5912\right)}^{0}), ({\Lambda }{b}^{0}{\left(5920\right)}^{0}), ({\Lambda }{b}^{0}{\left(6146\right)}^{0}), and ({\Lambda }{b}^{0}{\left(6152\right)}^{0}) in the ({\Lambda }{b}^{0}{\pi }^{+}{\pi }^{-}) mass spectrum is confirmed, and their masses are measured. The ({\Lambda }{b}^{0}{\pi }^{+}{\pi }^{-}) mass distribution exhibits a broad excess of events in the region of 6040–6100 MeV, whose origin cannot be discerned with the present data.