bug-bounty
(2)
Nebula Security
Nebula Security is an AI-native cybersecurity company from Y Combinator's Summer 2026 batch. Founded by world-class hackers - members of the world's #1 CTF team r3kapig, DEF CON finalists, Black Hat speakers, and a cybersecurity PhD - it pairs an autonomous code-scanning agent called VEGA with human expertise to audit software for vulnerabilities, from code-level bugs to architectural weaknesses. The team has earned $400K+ in bug bounties exploiting the Linux kernel and Chrome, and reported over a thousand vulnerabilities. Its pitch: 'Attackers already have AI. Get VEGA now.'
Cobalt
Cobalt is the pioneer of Pentest as a Service (PtaaS), pairing a curated community of vetted offensive-security experts (the Cobalt Core) with a SaaS platform that turns penetration testing from a months-long procurement exercise into an on-demand, continuous program. Founded in 2013, the company now serves 1,500+ customers and is leaning hard into AI-augmented offensive security.