HiddenLayer Raises $100M Series B Led by Delta-v Capital

Austin, Texas-based AI security company HiddenLayer has raised a $100 million Series B round led by Delta-v Capital, per funding data dated September 2, 2026. The round includes participation from M12 (Microsoft's Venture Fund), Booz Allen Ventures, Ten Eleven Ventures and Morgan Stanley.

What the Company Does

HiddenLayer protects agentic, generative and predictive AI applications across the full AI lifecycle. Its coverage spans discovery and supply-chain security through to attack simulation and runtime protection.

The company's AISec Platform performs two core functions:

Model and file scanning — scans AI models and file formats for tampering.
Runtime agent defense — defends AI agents against threats including prompt injection, manipulation and malicious tool use.

This dual focus reflects the expanding attack surface as enterprises move from experimenting with AI to deploying autonomous and generative systems in production.

Customers and Recognition

HiddenLayer counts financial services firms, large technology companies, and US defense and intelligence customers. The company is also a Gartner-recognized Cool Vendor for AI Security.

Notably, HiddenLayer states it secures AI for a leading frontier model provider with over 700 million weekly users. That scale of deployment is a significant reference point for a security vendor, indicating its technology operates in environments with extreme user volume and visibility.

The Investor Syndicate

The Series B brings together a mix of growth capital and strategic investors:

Delta-v Capital led the round.
M12, Microsoft's Venture Fund participated.
Booz Allen Ventures participated.
Ten Eleven Ventures participated.
Morgan Stanley participated.

The presence of Booz Allen Ventures is consistent with HiddenLayer's defense and intelligence customer base, while M12's involvement connects the company to the broader Microsoft ecosystem. Ten Eleven Ventures brings cybersecurity specialization, and Morgan Stanley's participation aligns with the company's financial services footprint.

Why This Round Matters

AI security has moved from a niche concern to a board-level issue as enterprises deploy agentic systems that can take actions, call tools and access data. Threats like prompt injection and malicious tool use are specific to this new class of applications, and runtime protection is increasingly viewed as a necessary control layer rather than an optional one.

HiddenLayer's positioning across the full lifecycle — from discovery and supply-chain security to attack simulation and runtime defense — gives it multiple entry points into enterprise security budgets. The $100 million Series B provides substantial capital to scale that platform at a time when demand for AI-specific security controls is expanding.

The involvement of both strategic corporate investors and specialized cybersecurity funds suggests confidence in the company's ability to serve regulated and high-security environments, including defense and intelligence.

What to Watch

With a frontier model provider among its references and a customer base spanning financial services, technology, and US defense and intelligence, HiddenLayer operates where security requirements are most stringent. How the company converts its Series B into expanded enterprise deployments — and whether it extends its lead in agentic AI runtime protection — will be the key measures to track.