Rein Security, a cybersecurity startup based in New York and Tel Aviv, has secured $25 million in a Series A funding round. The investment was co-led by Glilot Capital and Sienna Venture Capital, with participation from Corner Ventures, Atlacle, and RNP Capital Advisors. This latest injection of capital brings the company's total funding to $35 million.
Founded in 2024 by CEO Matan Bar-Efrat and CTO Netanel Rubin, the company currently employs 31 people. Since the product launch in January 2026, which followed an $8 million seed round, Rein reports an 8x increase in revenue and a 5x growth in its customer base. The platform is used by companies in the financial services, healthcare, and retail sectors, including Dun and Bradstreet and Lemonade.
The startup provides a runtime security platform for enterprise AI agents using patented sidecar technology. This solution monitors agents as they execute, allowing security teams to track code and resource access in real time. The platform is designed to block harmful actions without routing data to external parties, ensuring that sensitive information remains within the organization.
According to Gartner, the AI security market is projected to reach nearly $4.8 billion in 2027, representing a 68.7% increase from 2026. The market is expected to grow further to approximately $7.7 billion by 2028.
