Startup profile · funding coverage
Rein Security funding, valuation and investors
Runtime security platform that monitors and governs enterprise AI-agent behavior.
Keep track of Rein Security
Save this profile to your VCT watchlist for a quick return.
Funding, valuation & investors
Answer-first snapshotLatest funding
Series A
$25M · October 8, 2026
Latest known valuation
Not publicly disclosed
Total disclosed equity funding
$25M
Excludes debt, grants, acquisitions, secondaries, and IPO proceeds.
Current status
private
series a · New York, New York and Tel Aviv, Israel
Investors in latest funding
Lead: Glilot Capital , Sienna Venture Capital
Other: Corner Ventures , Atlacle , RNP Capital Advisors
Overview
Rein Security is a New York- and Tel Aviv-based cybersecurity company building runtime controls for enterprise AI agents. Its platform traces agent actions, enforces behavioral policies and blocks harmful actions before execution without routing customer data through a gateway or proxy.
Why Rein Security is interesting
Rein is attacking the security layer created when autonomous agents are allowed to read data, call APIs and change business systems without continuous human review.
Product & use cases
A runtime sidecar security layer for enterprise AI agents, combining action-level observability, behavioral governance, exploit prioritization and real-time blocking.
- Monitor and govern actions taken by customer-service and workflow agents
- Block prompt-injection-driven actions before execution
- Trace agent actions to source code and business outcomes
- Prioritize exploitable AI-agent vulnerabilities
Key facts
- $25M Series A co-led by Glilot Capital and Sienna Venture Capital in October 2026
- $35M total disclosed funding
- Company says revenue grew 8x and customer count 5x since its January 2026 launch
- Named customers include Lemonade and Dun & Bradstreet
Funding history (newest first)
Series A
2026-10-08 $25M- Glilot Capital (lead)
- Sienna Venture Capital (lead)
- Corner Ventures (participant)
- Atlacle (participant)
- RNP Capital Advisors (participant)
Investors in our directory
Funds linked from Rein Security's profile — open a fund page for stage focus and related deal articles.
Competitive landscape
Edge: Runtime visibility tied to the code and business outcome of each agent action, with inline enforcement that does not require customers to reroute data through a central proxy.
Rein competes in a crowded AI-security market, but emphasizes action-level runtime enforcement rather than posture dashboards or gateway filtering. Its moat will depend on deployment friction, coverage across agent frameworks, policy accuracy and the proprietary attack knowledge produced by its Agent Breakers team.
-
Noma Security direct
AI security posture and runtime protection for enterprise AI systems.
-
Prompt Security direct
Enterprise controls for generative-AI and agent usage.
-
Protect AI adjacent
Broader platform securing the machine-learning supply chain and AI applications.
-
Traditional application security tools alternative
Static scanners and gateways cover components but may miss agent behavior at runtime.
Industries
Market / IPO context
Editorial / static context — not a live quote.
Related funding articles
Venture Capital Tracker pieces that cover Rein Security's financing or category context.
FAQs about Rein Security
Practical answers founders, operators, and investors typically search for.
Last updated:
Editorial note: AI tools assisted with research, structure, or drafting. Venture Capital Tracker retains human editorial responsibility for factual accuracy, relevance, and source quality before publication.