Docker has made their hardened images free and open-source under Apache 2.0 license, providing access to over 1,000 security-focused base images. Hardened images address supply chain vulnerabilities by removing unnecessary packages and outdated dependencies from standard base images. Developers can swap existing base images with hardened equivalents with minimal changes to their Dockerfile, though some debugging tools may be missing. Docker also released hardened Helm charts that follow security best practices by default for Kubernetes deployments.