Concrete gravity dams may be subjected to several hazards that vary in intensity and can occur simultaneously. In current practice, stability assessments commonly rely on predefined load combinations, which provide a practical basis for verifying stability requirements but do not explicitly quantify how often different hazards may occur simultaneously. This paper proposes a modular framework for the multi-hazard stability assessment of concrete gravity dams. The framework uses hazard and material characterization to generate scenarios that are then evaluated for stability. Return periods are assigned to the generated load configurations and classified into usual, unusual, and extreme categories, allowing the results to be interpreted using current engineering criteria. Although the framework can be applied to different performance criteria, the case study presented in this paper focuses on sliding stability along potential sliding planes. Sliding stability is evaluated using the factor of safety and the main result is expressed as the probability of not meeting a target factor of safety as a function of the return period. The methodology is demonstrated using a concrete gravity dam case study. The results show how the framework can identify critical sliding planes, governing parameters, and the effect of updated material characterization. The proposed approach provides a practical intermediate step between deterministic stability checks and more detailed assessments, such as field investigations, laboratory testing, or refined finite-element analyses, by supporting the interpretation of multihazard performance and the prioritization of further investigations.