Depthfirst Raises $80 Million Series B at $580 Million Valuation to Build AI Security Intelligence

Depthfirst, a cybersecurity startup developing what it describes as a 'general security intelligence' for automatically identifying and remediating company vulnerabilities, has raised an $80 million Series B at a $580 million valuation, Forbes reported. The round brings total funding to $120 million, according to Forbes reporter Thomas Brewster, who described the company as building AI-powered defenses specifically designed to counter malicious uses of artificial intelligence by attackers. Depthfirst's platform is designed to continuously scan enterprise infrastructure, find security gaps, and generate remediation steps -- automating tasks that traditionally require large teams of security analysts. The company's pitch centers on the idea that AI-driven attacks are outpacing human defenders' ability to respond, and that only AI-powered defense can keep pace. The funding comes amid a surge of investor interest in AI-native cybersecurity companies. Traditional security vendors are under pressure to integrate AI capabilities, while a new wave of startups like Depthfirst is arguing that products built on AI foundations from the start will ultimately outperform retrofitted legacy tools. The $580 million valuation places Depthfirst among the more highly valued early-stage cybersecurity companies, reflecting the premium investors are placing on AI defense capabilities as enterprises grapple with increasingly sophisticated threats, including supply chain attacks of the kind that affected Cisco and Mercor this week. Depthfirst plans to use the Series B proceeds to expand its engineering team and accelerate product development. Forbes reported the round on March 31, 2026.