What is Container Vulnerability Scanning?

Container vulnerability scanning is the automated process of analyzing container images to identify security vulnerabilities, misconfigurations, and compliance violations. These tools examine every layer of a container image, comparing the installed packages, libraries, and binaries against databases of known vulnerabilities. Modern scanners go beyond simple package matching, analyzing Dockerfiles for security best practices and checking for exposed secrets or hardcoded credentials.

The scanning process typically begins by extracting the container image layers and creating an inventory of all installed components. This Software Bill of Materials (SBOM) includes operating system packages, programming language libraries, and application dependencies. The scanner then queries vulnerability databases such as the National Vulnerability Database (NVD), distribution-specific security advisories, and language-specific vulnerability feeds to identify known security issues affecting these components.

Advanced container scanners provide more than just a list of vulnerabilities. They offer contextual information about each finding, including severity ratings, available fixes, and potential impact. Some scanners can trace vulnerabilities to specific image layers, helping developers understand how the vulnerability was introduced. This detailed analysis enables teams to prioritize remediation efforts based on actual risk rather than just vulnerability counts.