Vulnerability research is one of the most effective ways to prevent zero-day attacks, making it a highly sought-after skills set in the cybersecurity realm. This book is designed to help newcomers navigate the intersection of disciplines needed to find unknown security flaws before they can be exploited. In it, author Eugene 'Spaceraccoon' Lim - an award-winning white-hat hacker - presents a comprehensive roadmap of starter strategies in vulnerability research that will enable you to begin hunting zero days right away. Delving into the intricacies of code review, reverse-engineering, fuzzing, and more, Lim guides you step-by-step on how to discover real-world vulnerabilities in the wild. Even experienced researchers can benefit from Lim's insights, expanding their toolkits and discovering new zero days along the way. Learn how to: Strategically select appropriate targets for vulnerability research, Master the art of code review and automate variant analysis, Reverse-engineer software with a focus on discovering vulnerabilities, Bootstrap fuzzing harnesses and analyze crashes, and Develop exploits and proof-of-concepts. From Day Zero to Zero Day is your gateway to mastering vulnerability research - an increasingly critical domain in safeguarding our digital landscape.