Clair

Clair is an open-source container image and artifact vulnerability analysis system (container security) that indexes image contents and reports known vulnerabilities based on external security data sources.

• Static vulnerability analysis of container images and related artifacts (container security)
• Indexing of image contents such as packages and distribution metadata (software asset inventory)
• Matching indexed contents against vulnerability databases and security advisories (vulnerability management)
• HTTP-based APIs for indexing, querying, and retrieving vulnerability reports (API-based security service)
• Integration with container registries, including Quay, for automated image scanning workflows (DevSecOps integration)

More About Clair

Clair is an open-source project from Red Hat that provides static analysis of container images and similar artifacts to identify known vulnerabilities before deployment in production environments. Positioned in the container security and vulnerability management category, Clair focuses on extracting detailed metadata from images and correlating that metadata with external vulnerability data sources, such as distribution security advisories and Common Vulnerabilities and Exposures (CVE) feeds.

The project operates by indexing container image contents, including package lists, Operating System (OS) distribution information, and other relevant components (software asset inventory). This indexed data is then evaluated against configured vulnerability databases (vulnerability management), allowing security and platform teams to query which images, layers, or artifacts are affected by particular CVEs. Clair exposes this functionality through HTTP-based APIs, which enterprises integrate into registries, build pipelines, and security tooling to automate vulnerability detection and reporting.

Clair’s architecture is service-oriented and commonly deployed as one or more services backed by a database that stores image indexes and vulnerability data (cloud-native infrastructure). The system ingests vulnerability information from upstream OS and package-maintainer sources, normalizes it, and stores it for matching against indexed image contents. Its Application Programming Interface (API) surface supports operations for submitting manifests or layers for indexing, retrieving the resulting index reports, and querying vulnerability matches associated with those indexes (API-based security service).

In enterprise environments, Clair is used as a component within container registry platforms and DevSecOps workflows (DevSecOps tooling). For example, it is integrated with Red Hat Quay to provide image scanning capabilities directly in the registry experience, enabling teams to enforce policies on image promotion or deployment based on vulnerability status. Continuous Integration and Continuous Deployment (CI/CD) systems can call Clair’s APIs during build or release stages to ensure images meet organizational security thresholds before being pushed to production clusters.

Clair is designed for extensibility and interoperability within container-native ecosystems (cloud-native security). It supports multiple OS distributions and package ecosystems through dedicated indexers and updaters, as documented in the project’s official materials. This modularity allows operators to configure which ecosystems and data sources are relevant to their workloads. From a directory and taxonomy perspective, Clair fits into container image scanning, vulnerability assessment, and registry-integrated security services, serving platform, security, and compliance teams that need programmatic insight into the vulnerability posture of containerized workloads.