Refusal boundaries are predefined constraints within AI or cybersecurity systems that prevent the system from responding to requests considered unsafe, unethical, or potentially harmful. These boundaries are essential for maintaining security, privacy, and ethical standards, especially in environments where dual-use or malicious requests could exploit system capabilities. Refusal boundaries are implemented through a combination of technical safeguards, policy guidelines, and automated detection mechanisms. In cybersecurity, these boundaries help ensure that sensitive operations, such as sharing exploit code or bypassing authentication, are blocked, thereby reducing the risk of abuse or unintended consequences. They play a critical role in responsible AI deployment and secure system design.