NATO Locked Shields 2026

Imagine this: you're responsible for keeping an entire country's power grid, banking system, and military communications online — and a team of the world's best offensive hackers is trying to bring it all down. That's Locked Shields in a nutshell.

Organized by the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) since 2010, this exercise has grown from a small technical drill into the most complex cyber defense exercise on the planet. It's not just about patching servers. Teams face legal dilemmas, media crisis scenarios, and forensic puzzles — all while fending off thousands of attacks in real time.

What Makes 2026 Special

This year's edition introduces AI-enhanced attack scenarios for the first time, reflecting the reality that adversaries now use machine learning to scale their operations. Blue Teams will need to defend against automated reconnaissance, adaptive malware, and AI-generated phishing — the same threats that real-world defenders encounter daily.

The exercise also expands its critical infrastructure scope, adding 5G telecommunications networks and cloud-native environments to the scenarios. Teams won't just defend on-premise servers — they'll protect hybrid architectures that mirror actual government and enterprise setups.

Ukraine's Role

Ukraine's participation in Locked Shields carries unique weight. While most teams train for hypothetical scenarios, Ukrainian defenders bring experience from years of real cyber conflict — defending against Sandworm's attacks on the energy grid, fighting off wipers during the full-scale invasion, and maintaining digital resilience under constant pressure. Their presence elevates the entire exercise.

Why This Matters for the Industry

Locked Shields isn't an academic exercise. The lessons from each edition directly influence how NATO nations structure their cyber defense, train their teams, and coordinate across borders. For cybersecurity professionals, following the outcomes of Locked Shields provides a window into what the world's top military defenders consider the most pressing threats — and how they're preparing.