Security teams can find thousands of vulnerabilities across an enterprise network. The harder problem is knowing which ones attackers can actually exploit—and whether the fix worked.
Horizon3 has raised an oversubscribed $250 million Series E at a valuation above $2 billion, more than tripling its $650 million Series D valuation in just over a year. The round was co-led by NightDragon and New Enterprise Associates.
New investors included Acrew Capital, Blue Cloud Ventures, Demeter Group, EDBI, PSG, SAIC and Sapphire Ventures. Craft Ventures, Prosperity7 Ventures, Qualcomm Ventures, Ridge Ventures and SignalFire returned. NightDragon founder Dave DeWalt and managing director Morgan Kyauk will join Horizon3’s board.
Co-founded by Snehal Antani and Anthony Pillitiere, Horizon3 operates NodeZero, an autonomous penetration-testing platform that safely attacks production environments to uncover exploitable paths created by weak credentials, identity gaps and misconfigurations.
NodeZero then recommends fixes and tests the environment again to confirm that remediation worked. This continuous hack, fix and verify model moves security validation beyond annual penetration tests and static vulnerability lists.
Horizon3 reports more than 7,000 customers, 310,000 production tests and 120% year-over-year ARR growth. Its customers include major banks, healthcare networks, government agencies and four Fortune 10 companies. These figures are company-reported.
The funding will expand sales, marketing and channel operations, deepen Horizon3’s EMEA presence and support entry into Singapore and Australia. Product investment will focus on AI defenders that can remediate findings directly, creating a learning loop between autonomous attackers and defensive agents.
The next test is whether Horizon3 can automate remediation without removing the control, evidence and