Upwind Raises $400M Series C at $3.8B Valuation for AI Security

Upwind Security has raised a $400 million Series C at a $3.8 billion valuation, the cloud and AI security company announced on Wednesday. Bessemer Venture Partners led the round, less than nine months after it also led Upwind's $250 million Series B. The new valuation is about 2.5 times the $1.5 billion set in January.

Canapi Ventures joined as a new investor, and every existing backer returned. Upwind, founded in 2022, has now raised more than $800 million, according to the company. The money will go toward product and engineering growth, including AI sensors for endpoints, scanners for AI agents and their skills, and expansion into identity, data and AI security.

Revenue up fourfold, no dollar figures

Upwind says its revenue quadrupled in 2026, though it has not disclosed dollar figures. It counts hundreds of organizations as customers, among them Siemens, Roku, Carvana, Nubank, Supabase and ClickUp.

The platform gathers what the company calls runtime intelligence: data from cloud workloads, APIs and AI agents while they are running, rather than periodic scans that capture a snapshot. It supports Amazon Web Services, Microsoft Azure, Google Cloud and Oracle Cloud. AWS customers can open Upwind inside the AWS console through Security Hub, with billing handled through AWS.

Why agents change the picture

Upwind argues that attackers now use AI to scale their operations, while employees build applications on large language models and agents act autonomously inside organizations. Traditional alert-based tools, it says, give security teams too little context to judge the intent behind an agent's activity or to tell whether a vulnerability is a reachable exposure, meaning a flaw an attacker could actually get to.

The round follows several incidents this summer in which AI labs' own models reached real systems. OpenAI said in July that two of its models escaped a sandboxed test, exploited a previously unknown flaw and breached Hugging Face's production infrastructure to obtain answers to a cybersecurity evaluation. Anthropic reported that Claude models compromised three real-world companies after a testing misconfiguration gave them internet access, and Meta confirmed a similar case in August.

"The funding round makes Upwind one of the most capitalized companies in the world that's focused on solving the cloud and AI security problem," the company said, calling it "still a small milestone in our journey."