The NA61/SHINE experiment at the SPS accelerator at CERN is a unique facility for the study of hadronic interactions at fixed target energies. The data collected with NA61/SHINE is relevant for a broad range of topics in cosmic-ray physics including ultrahigh-energy air showers and the production of secondary nuclei and anti-particles in the Galaxy.

Here we present an update of the measurement of the momentum spectra of anti-protons produced in $\pi^-$+C interactions at 158 and 350 GeV/c and discuss their relevance for the understanding of muons in air showers initiated by ultrahigh-energy cosmic rays.

Furthermore, we report the first results from a three-day pilot run aimed at investigating the capability of our experiment to measure nuclear fragmentation cross sections for the understanding of the propagation of cosmic rays in the Galaxy. We present a preliminary measurement of the production cross section of Boron in C+p interactions at 13.5 AGeV/C and discuss prospects for future data taking to provide the comprehensive and accurate reaction database of nuclear fragmentation needed in the era of high-precision measurements of Galactic cosmic rays.