Modern avionics systems are increasingly interconnected with IP‑based data networks, passenger connectivity platforms, ground systems, data recording technologies, high‑speed interfaces, and wireless communications. While this integration enables greater efficiency and innovation, it also expands the potential attack surface for cyber threats. As a result, cybersecurity has become a critical concern for the aerospace industry. With rapid technological advancement, protecting avionics systems from cyber risks is now viewed as just as essential as ensuring their physical safety. Addressing this challenge requires a comprehensive approach that spans threat identification, risk assessment, mitigation strategies, regulatory certification alignment (including standards such as DO‑178C and DO‑254), and lifecycle‑wide security integration.