Build-time image scanning leaves critical gaps once containers are running in production. Key overlooked areas include running containers as root, overly permissive RBAC and network policies, lack of real-time threat detection, and configuration drift. Practical mitigations include enforcing non-root execution via Pod Security Standards, default-deny network policies, kernel-level runtime monitoring tools (with 1–2.5% CPU overhead), read-only root filesystems, and continuous scanning beyond deployment time. Recent runC CVEs from 2025 illustrate that the runtime layer is an active attack vector enabling container escape and privilege escalation.
Table of contents
What Container Runtime Security EntailsCommon Runtime GapsRunning Containers as RootOverly Permissive RBAC and Network PoliciesLack of Real-Time Threat DetectionIgnoring Configuration DriftRuntime Layer as Attack VectorPractical Runtime Security PostureWhy Deployment Time Security Alone Doesn’t Cut ItRelated10.1K Impressions