An exploit is a method or piece of code that takes advantage of vulnerabilities in software, applications, networks, operating systems, or hardware, typically for malicious purposes. The term "exploit" derives from the English verb "to exploit," meaning "to use something to one’s own advantage." Exploits are designed to identify flaws, bypass security measures, gain unauthorized access to systems, take control of systems, install malware, or steal sensitive data. While an exploit by itself may not be a malware, it serves as a vehicle for delivering malicious software by breaching security controls.

Estimates of the economic cost of cyberattacks that rely on exploits vary widely depending on methodology and scope; a 2020 McAfee/CSIS report estimated the global cost of cybercrime at more than US$1 trillion annually. In response to this threat, organizations are increasingly utilizing cyber threat intelligence to identify vulnerabilities and prevent hacks before they occur.