Measurements of the anomalous magnetic moment of leptons ( \(a_{l} = (g-2)_{l}/2\) ) provide stringent tests of the Standard Model (SM) and possible hints of new physics. While electron and muon (g-2) are precisely known, the short lifetime of the tau ( \(\tau \) ) lepton prevents precession measurements. In this note the latest (g-2) measurement of the \(\tau \) using ultraperipheral Pb-Pb collisions, with an integrated luminosity of up to 1.7 nb \(^{-1}\) , collected by CMS at \(\sqrt{s_{_{\textrm{NN}}}} =\) 5.02 TeV will be presented. The Z \(^4\) (Z=84 for Pb) dependence enhances photo-production compared to pp and e \(^{+}\) e \(^{-}\) collisions. This analysis improves the previous CMS result by adding three more decay modes, increasing luminosity fourfold, and incorporating cross-section and kinematic distributions. The measured \(\gamma \gamma \rightarrow \tau ^{+}\tau ^{-}\) cross-section is the most precise to date, while the \(a_{\tau }\) result is among the most precise in Pb-Pb and e \(^{+}\) e \(^{-}\) collisions.