CVE-2025-4953

A flaw was found in Podman. In a Containerfile or Podman, data written to RUN --mount=type=bind mounts during the podman build is not discarded. This issue can lead to files created within the container appearing in the temporary build context directory on the host, leaving the created files accessible.

This issue is classified as Moderate rather than Important because exploitation requires several preconditions: an attacker must have unprivileged access to the host during the build process, the container build must include long-running steps (e.g., RUN sleep) that prolong the existence of the temporary build context, and files must be created with overly permissive permissions (e.g., 4777). The vulnerability does not allow remote code execution or compromise of running containers, and it only exposes files temporarily present in the build context. Therefore, while it can lead to information disclosure, the scope and impact are limited to local users with concurrent access, making the overall risk moderate.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Avoid long-running build steps and overly permissive file permissions. Use RUN --mount=type=secret for sensitive data instead of bind mounts.