Cosmic-ray antinuclei are particular informative probes of high-energy processes in the Galaxy and can hint at exotic sources of energetic particles, such as dark-matter annihilation. Antinuclei are expected to be produced at a low level in conventional reactions, and their flux can even be dominated by exotic contributions. However, the interpretation of cosmic antinuclei measurements requires a good understanding of all processes involved in their creation and propagation and a realistic estimate of the involved modeling uncertainties to distinguish potential exotic contributions from ordinary production.
In this contribution, we review the current understanding of the production and propagation of charged cosmic-ray antinuclei in the Galaxy and the modeling of their fluxes, with a special focus on cosmic-ray antiprotons. In particular, we quantify systematic deviations of the modeled flux that arise from inaccuracies of the numerical solution of the propagation equation, different models of propagation processes, and different models of the antiproton-production cross-section.