What Is an Exploit? Vulnerabilities and Threat Mitigation

This document is a concise primer on software exploits: it defines what an exploit is, outlines common exploit types (e.g., RCE, buffer overflow, SQL injection, XSS, privilege escalation, zero-day), describes the exploit lifecycle and where exploits occur across the technology stack, cites historical examples (Log4Shell, Heartbleed, MOVEit), and provides recommended defenses including vulnerability management, timely patching, network segmentation, monitoring threat intelligence, secure development practices, and supply-chain risk mitigation.