The OSV.dev database indexes known vulnerabilities (CVEs) for open source packages, including Linux distribution packages used in container base images. The Image Vulnerability Lookup builds an OSV API query for an image and shows the known vulnerabilities.
It maps common base images to their OSV ecosystem, queries by name + tag/version, and parses the response into a readable list of IDs, aliases (CVE numbers), severity and references. The request building and response parsing are pure functions that are unit-tested. Network failures are handled gracefully in the UI.
Nothing about your image is uploaded except its name and version to the public OSV API.