Rein Security Raises $25M Series A

Rein Security, based in New York and Tel Aviv, provides an AI-native runtime security platform designed to secure enterprise AI agents. The company announced a $25 million Series A funding round, bringing its total capital raised to $35 million.

Investors

The round was co-led by Glilot Capital and Sienna Venture Capital. Additional participation included Corner Ventures, Atlacle, and RNP Capital Advisors.

Rein Security Use of Funds

Rein Security plans to use the new capital to accelerate product innovation, advance research into agentic AI security, and support global hiring initiatives.

About Rein Security

Founded in 2026, Rein Security provides a platform that operates at runtime, offering visibility and governance over AI agent activity to prevent harmful actions. The company enables enterprises to deploy and scale AI agents with security guardrails that defend against both internal agent misconfigurations and external AI-driven attacks.

Funding Details

Company Website: https://reinsec.io

Company: Rein Security
Raised: $25M
Round: Series A
Funding Date: October 2026
Lead Investor: Glilot Capital, Sienna Venture Capital
Additional Investors: Corner Ventures, Atlacle, RNP Capital Advisors
Software Category: Cybersecurity