Horizon3 Secures $250 Million to Lead AI-Versus-AI Cyber Defense
22:21 · August 3, 2026 · RSS APP - Defense Artificial Intelligence

Horizon3 raised $250 million in a Series E funding round to continue growing its NodeZero platform that uses artificial intelligence to defend against
Summary
Horizon3 closed a $250 million Series E round that tripled its valuation to more than $2 billion, with NightDragon and NEA as co-leads. The capital will support scaling of the NodeZero platform, which performs continuous, autonomous penetration testing inside live production environments. The system identifies vulnerabilities, supplies prioritized remediation guidance, and automatically retests to confirm that fixes have taken effect.
NodeZero also monitors for signs of AI-driven attackers and can demonstrate their presence within an environment. Horizon3 reports 120 percent year-over-year growth in annual recurring revenue and now serves more than 7,000 organizations, including four Fortune 10 companies. Expansion plans include new operations in Singapore and Australia alongside deeper coverage across the EMEA region.
The company frames its approach as an explicit response to AI-versus-AI cyber conflict. Co-founder and CEO Snehal Antani noted that the volume of vulnerabilities is expected to rise sharply, yet only a small fraction will be immediately exploitable. Rather than simply cataloging issues, the platform is designed to close the loop between detection and verified remediation through iterative AI-driven feedback between simulated attacks and defensive actions.
Why it matters
Article covers dual-use AI cyber defense with military/security relevance and EMEA growth plans that include the Netherlands; directly addresses AI/ML applications in proactive defense for industry and government users.










