UbuntuGuard: A Culturally-Grounded Policy Benchmark for Equitable AI Safety in African Languages. - Tassallah Abdullahi; Macton Mgonzo; Mardiyyah Oduwole; Paul Okewunmi; Abraham Toluwase Owodunni; Ritambhara Singh; Carsten Eickhoff (CoRR, 2026)