The round tripled Horizon3’s valuation to over $2 billion, up from the $650 million valuation it achieved about a year ago in its Series D, the company said in a Monday (Aug. 3) press release.
Horizon3’s NodeZero platform autonomously and safely attacks an organization’s own production environment to reveal vulnerabilities, provide guidance for fixing them and instantly verify that they’ve been remediated, according to the release.
The platform also helps detect AI attackers and prove they are inside the environment, the release said.
Horizon3 has gained 120% year-over-year growth in annual recurring revenue (ARR) and now protects more than 7,000 organizations globally, including four Fortune 10 enterprises, per the release.
With its new funding, Horizon3 will scale its go-to-market operations; continue its international expansion by entering Singapore and Australia and deepening its presence across the Europe, Middle East and Africa (EMEA) region; and accelerate its product roadmap, according to the release.
“We’re about to see an explosion of vulnerabilities, most of which won’t matter, but a small percentage will be immediately exploitable,” Horizon3 Co-Founder and CEO Snehal Antani said in the release. “The goal of running pentests isn’t to find problems, it’s to quickly fix exploitable problems that matter. We started with pentesting, evolved to be a proactive security platform, and will now accelerate remediation by creating AI learning loops between attackers and defenders.”
Pentesting, or penetration testing, is a cybersecurity technique in which ethical hackers use the tactics of the most sophisticated adversaries to discover and fix security vulnerabilities before they can be exploited.
Horizon3’s Series E funding round was co-led by NightDragon and NEA.
NightDragon Founder and CEO Dave DeWalt said in the release that Horizon3 “coined the concept of cyber warfare being AI vs. AI, and that future has arrived.”
The FBI’s Internet Crime Complaint Center (IC3) said in April that it received 22,364 internet crime complaints that contained references to AI in 2025.
PYMNTS reported Friday (July 31) that AI is making software vulnerabilities easier to find and that the next cybersecurity advantage may belong to the company that can change permissions, transaction limits and system access before those bugs become business events.
