This volume constitutes the proceedings of the 8th International Conference on Machine Learning for Cyber Security, ML4CS 2026, held in Nadi, Fiji, on July 6–10, 2026.

The 28 full papers were carefully reviewed and selected from 101 submissions. These papers were organized in following topical sections:Intrusion Detection and Network Traffic Analysis; Malware, Ransomware, and Malicious Code Detection; Federated Learning Security and Privacy-Preserving Machine Learning; LLM and Prompt Security; Privacy, Authentication, and Content Protection; and  Trustworthy AI, Explainability, and Cyber Governance.