> For the complete documentation index, see [llms.txt](https://cortex-docs.paloaltonetworks.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://cortex-docs.paloaltonetworks.com/cortex-xsiam/cloud-security/base-images-rule.md). # Base image rules A **Base Images** rule defines which registry images your organization considers foundational base images and maps derived images to them. This association provides image lineage visibility, helping you trace vulnerabilities to their source and apply remediation at the base image level. A **Base Images** rule associates registry images (for example, ubuntu:22.04) as designated base images. When a rule is applied, it creates a **BASE\_REFERENCE** relation between images, enabling bidirectional tracing so you can: * Identify the base image for any given image * View all dependent images derived from a specific base image By creating **Base Images** rule, you can: * Identify approved base images across your organization * Map Registry and Runtime images to base images for full lineage visibility * Identify affected base images during vulnerability investigations * Identify all dependent images impacted by a vulnerable base image * Use base image associations in policies, queries, and filters --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter: ``` GET https://cortex-docs.paloaltonetworks.com/cortex-xsiam/cloud-security/base-images-rule.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.