The study of excited $\Lambda_{\mathrm{b}}^0$ states and their mass measurement by the CMS experiment is reported, as well as the observation of the $\Lambda_{\mathrm{b}}^0\rightarrow \mathrm{J}/\psi\Lambda\phi$ decay and the measurement of its branching fraction, relative to the $\Lambda_{\mathrm{b}}^0\rightarrow \psi(\mathrm{2S})\Lambda$ decay. Both analyses use proton-proton collision data collected at $\sqrt{s} = 13$ TeV.