Horizon3
Horizon3 runs autonomous attack testing to find and verify exploitable weaknesses in production environments.
- Categories
- Penetration testing, Attack surface management, Breach and attack simulation, Vulnerability management
- Based in
- San Francisco, United States
- Founded
- 2019
- Ownership
- Private
About Horizon3
Horizon3.ai sells the NodeZero platform, which runs autonomous penetration tests in production environments. It serves large organisations, including governments, Fortune 10 companies, healthcare providers, banks, energy firms, manufacturers and defence contractors. The platform finds exploitable attack paths, guides fixes and verifies that remediation worked. NodeZero uses AI to execute real attack techniques without agents. It chains weaknesses together as an attacker would, then safely exploits them. The platform provides proof of exploitation, prioritised impacts and detailed fix guidance. It also offers a password audit, tripwires for detecting lateral movement, and rapid response to known exploited vulnerabilities. Tests can be scheduled to run continuously, and results are shown in a dashboard with attack paths and remediation steps.
Products
- NodeZeroAn autonomous penetration testing platform that safely runs real attacks in production to find, fix and verify exploitable risks.
- NodeZero WebApp PentestingA product for hacking web applications to find exploitable weaknesses.
- NodeZero TripwiresA feature that detects live lateral movement during tests.
- NodeZero InsightsA capability that provides visibility into test results and security posture.
- AD Password AuditA tool that verifies the effectiveness of credential policies by checking for exposed passwords.
- Rapid ResponseA service that integrates exploitable known exploited vulnerabilities within hours.
Ownership and deals
- Raised $250m in a Series E roundInvestors NightDragon and New Enterprise AssociatesReport on the Horizon3 funding round of August 2026 (opens in a new tab)
- Raised fundingInvestor Prosperity7 VenturesReport on the Horizon3 funding round of January 2026 (opens in a new tab)
- Raised $73mReport on the Horizon3 funding round of May 2025 (opens in a new tab)
- Raised $40m in a Series C roundInvestor Craft VenturesReport on the Horizon3 funding round of August 2023 (opens in a new tab)
Acquisitions come from SecurityWeek's monthly M&A round-ups from 2021 onwards, from Cybersecurity Ventures' quarterly M&A reports for 2020, and a few from Wikipedia lists. Funding rounds from 2022 onwards come from Return on Security's weekly Security, Funded newsletter. These are dated to the month. A few deals added from the news are dated to the day. Smaller deals may be missing. Amounts are in US dollars.