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Xiaochuan Yu

Xiaochuan Yu

Co-founder of Nebula Security, YC 26. Security research, CTF player, #1 CTF team in the world in 2025 on CTFtime, DEFCON 2023/2024/2025 finalist, research published at USENIX Security, BlackHat USA | xia0.sh

Co-founderNebula Security logoNebula Security· Summer 2026🇺🇸 La Jolla Shores, California, United States
in LinkedIn𝕏 @Nyaaaaa_ovo
2026Co-founder· Nebula Security (YC S26)
Founder · since 2026
Company
Nebula Security (YC S26)
Role
Co-Founder
current
Stage
—
no public source
Raised
—
no public source
Based
San Francisco, California, United States
current
Founder / co-founder — the company's markEmployee / research role
Source: LinkedIn work history
Profile coverage5 of 7 · missing posts, contact
Nebula Security logo
Nebula Security

Building Mythos for everyone

Summer 2026

Experience

Career

  • Nebula Security (YC S26) logo

    Nebula Security (YC S26)

    Co-founder

    Co-Founder · San Francisco, California, United States · 2026 – Present

    2026
  • Zellic logo

    Zellic

    Security Reseacher · 2025 – 2026

    2025

Bio

Founder at Nebula Security (YC S26). Hacked into iPhone, Chrome, Firefox, Safari, QEMU, and various things in your daily life. DEFCON finalist for 3 consecutive years. $200k+ Bug Bounty in Chrome. Core member of r3kapig, the #1 hacking team in the world in 2025, on CTFTime. M.S. from UC San Diego. Research published at USENIX Security, BlackHat. Ph.D. droped out.