Nicolas just found a vulnerability on a public-facing system that is considered a zero-day vulnerability. He sent an email to the owner of the public system describing the problem and how the owner ca

Red hat hackers are vigilante actors known for aggressively counter-attacking black hat hackers using offensive means, not for performing coordinated vendor disclosure.

White hat hackers operate ethically within legal and moral boundaries, identifying vulnerabilities and disclosing them responsibly to the affected parties - as Nicolas did by notifying both the system owner and Microsoft. This coordinated disclosure approach is the defining behavior of white hat hacking, where the goal is to help organizations remediate weaknesses rather than exploit them for personal gain or disruption.

Black hat hackers exploit discovered vulnerabilities for malicious purposes, personal gain, or disruption without notifying affected parties.

Gray hat hackers typically exploit vulnerabilities without prior authorization before disclosing them - Nicolas disclosed without any exploitation, which is white hat behavior, not gray hat.