Cybersecurity startup Island valued at $6.4 billion amid AI agent security risks

Sept 24 : Cybersecurity startup Island said on Thursday it raised $400 million in a funding round that valued it at $6.4 billion, signalling growing interest in the sector as rapid adoption of artificial intelligence creates rampant new security risks.

The latest funding values Island at more than 30 per cent above its $4.8 billion valuation in a 2025 funding round.

Investors are pouring money into cybersecurity companies as businesses and governments grapple with new security risks, including rogue AI agents that can act beyond their intended controls and potentially gain unauthorized access to sensitive systems, data and online services.

Earlier on Thursday, Australia said an OpenAI agent breached a government health data portal in June, gaining unauthorized access to files. OpenAI has also faced scrutiny since it disclosed in July that rogue AI agents had bypassed internal controls, accessed the open internet and coordinated actions.

Dallas-based Island, which develops enterprise security tools, said the funding will fuel the company's next phase of growth and innovation as companies scale AI agents and modernize workflows.

The Series F funding round was led by Evolution Equity Partners, with participation from existing investors Prysm Capital, Sequoia Capital, Coatue Management, Cyberstarts, Insight Partners and J.P. Morgan Growth Equity Partners.

Island said it employs 1,000 people and has doubled its annual recurring revenue every fiscal year since its launch in 2022. The company lists PayPal, Amazon and Pfizer, among others, as customers on its website.