The NIST Secure Software Development Framework (SSDF) is a set of practices for building software with security built in, not added at the end. It guides teams to address secure design, code review, dependency management, testing, and patching across the software development lifecycle. The goal is to reduce avoidable vulnerabilities before software reaches production.
SSDF matters because many modern attacks exploit weaknesses introduced during development, such as insecure APIs, exposed services, or unreviewed third-party components. In defense, organizations use SSDF to assign clear ownership for fixes, improve release discipline, and shorten remediation time when flaws are found by human testers or defensive AI tools. In practice, it turns security into an engineering process, which is essential when attackers and defenders can both move quickly.