Information disclosure via malicious container image environment variables

Summary

Podman is a tool for managing OCI containers and pods. From 1.8.1 until 5.8.4, a container image that contains a environment variable with just a key and no value can trick podman into passing that variable from the host into the container. This is made worse by the fact that using an asterisk (*) will cause podman to pass all host variables into the container. So essentially a malicious image can exfiltrate all podman environment variables that are set in the session from where the container is launched. This vulnerability is fixed in 5.8.4 and 6.0.0. A flaw was found in Podman, a tool for managing OCI containers and pods. A malicious container image can be crafted with an environment variable that has a key but no value, or an asterisk (*), to trick Podman. This vulnerability causes Podman to pass host environment variables into the container. Consequently, a malicious image could exfiltrate all Podman environment variables set in the session from which the container is launched, leading to information disclosure. Red Hat severity: Important — CVSS 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N). Weakness: CWE-914. Fixed by RHSA-2026:29954 — update the affected packages (`sudo dnf update`). Affected Red Hat products: Red Hat Hardened Images.