Harmonic Security, a company that checks what staff share with AI tools at work, has raised $50 million in a Series B funding round led by Crosspoint Capital Partners, the company announced on 14 October 2026. Existing investors also took part.
Harmonic says the round was oversubscribed and brings its total funding to $76 million. It did not disclose its valuation. According to SiliconANGLE, its previous raise was a $17.5 million Series A led by Next47 in October 2024.
What Harmonic does
When employees use AI chatbots and assistants, they can paste in sensitive material, such as customer data or passwords. Harmonic’s software inspects what an employee sends to an AI tool before it gets there.
It uses its own small language models to read each interaction in context, in milliseconds. Harmonic says that is “enough to tell a developer referencing a schema apart from someone pasting live credentials.” In other words, it aims to block the risky case without stopping normal work.
Over the past year, Harmonic says it has extended this from AI tools used in a web browser to desktop AI apps and AI agents. It also offers a “Usage Intelligence” layer that shows managers which AI uses are paying off.
New integrations
Harmonic says it is listed among the integrations for Agent Builder, a tool in Cisco’s Cloud Control platform announced at Cisco Live, connecting through Model Context Protocol, a common standard for linking AI tools. It has also built a connection to Anthropic’s Claude Compliance API, which gives security teams activity logs from Claude, and the content of conversations for Claude Enterprise customers.
The company’s figures
According to Harmonic, it covers millions of employees at more than 100 companies, including some of the world’s largest, and has more than 90 staff in the US and UK. These are the company’s own figures. It plans to use the money to hire more engineers and sales staff on both sides of the Atlantic, and has signed distributors Climb and Distology.
“Every board I talk to is asking two questions: how do we reduce the risk of AI use, and are we getting value? Most vendors struggle to answer the first, yet we address both,” said Alastair Paterson, Harmonic’s chief executive and co-founder.
“As organizations embrace AI, they shouldn’t have to choose between moving quickly and maintaining control,” said Zach Sivertson, managing director at Crosspoint Capital Partners.
What this means
- Workplace AI is a security problem. Companies want staff to use AI without leaking secrets into it.
- AI agents widen the gap. Harmonic is following AI from the browser to desktop apps and agents.
- Investors are backing AI security. This round follows a run of funding for firms that monitor and control AI use.
Sources
- Harmonic Security, “Harmonic Security Raises $50 Million Series B, Enabling Safe AI Adoption for Millions More Employees”, Business Wire, 14 October 2026. https://www.businesswire.com/news/home/20261014886358/en/ (read via the finanznachrichten.de reprint: https://www.finanznachrichten.de/nachrichten-2026-10/69835891-harmonic-security-raises-dollar-50-million-series-b-enabling-safe-ai-adoption-for-millions-more-employees-004.htm)
- SiliconANGLE, “Harmonic Security raises $50M to govern how employees use AI tools”, 14 October 2026. https://siliconangle.com/2026/10/14/harmonic-security-raises-50m-to-govern-how-employees-use-ai-tools/
