Horizon3.ai raises $250M at $2B-plus valuation for autonomous pentesting
Autonomous security solutions startup Horizon3.ai Inc. today announced it has raised $250 million in a Series E round on a valuation of more than $2 billion to build out its sales operation and expand into Australia and Singapore. Horizon3.ai closed its Series D in June 2025 at a valuation of $650 million.
Horizon3.ai’s NodeZero platform attacks its customers’ own networks. The tests run against live production systems, and Horizon3.ai says nothing breaks. A single run chains weak credentials, misconfigurations and identity gaps into a working attack path, the same sequence a real intruder would use. Fix guidance comes with the findings. NodeZero re-runs the test afterward to confirm the path is closed.
NodeZero can also seed an environment with honeypots while it tests. Horizon3.ai sells the decoys as a cheap way to catch an AI-driven attacker that is already inside a network.
Horizon3.ai says NodeZero is now used by more than 6,500 organizations, up from about 3,000 at the Series D. Customers include the U.S. National Security Agency, the Cybersecurity and Infrastructure Security Agency, four Fortune 10 companies, multinational banks and healthcare networks. Annual recurring revenue grew 120% year-over-year, and the platform has now run upwards of 300,000 pentests in production, a volume of attack data the company treats as its hardest asset for a rival to copy.
