The text discusses the zero trust security model as an essential framework for enhancing network security across the software development lifecycle, particularly within Continuous Integration and Delivery (CI/CD) pipelines. This model operates on the principle that no user, device, or transaction is inherently trustworthy, requiring stringent authentication and authorization to safeguard sensitive resources. By implementing zero trust principles, organizations can reduce potential attack surfaces, improve compliance with industry standards, and maintain a secure development environment. CircleCI's security features, such as granular role-based access control, OpenID Connect (OIDC) tokens, and comprehensive audit logs, are highlighted as effective tools for integrating zero trust security into CI/CD pipelines. This approach not only minimizes risks from unauthorized access and data breaches but also supports a consistent, secure, and efficient software delivery process.