A malicious OCI registry can instruct Flatpak to create hardlinks to arbitrary host files during the extraction of an OCI archive. When a user installs or updates a Flatpak application from such a registry, the hardlinks allow the attacker to read any files that the Flatpak process can access, including sensitive host files such as /etc/shadow for system‑wide installs running as root. This vulnerability represents a path traversal via hardlink misuse and results in unauthenticated disclosure of host file contents.

The flaw affects Red Hat Enterprise Linux 10, 7, 8, and 9 systems that use the Flatpak runtime to install or update applications from OCI remotes. The issue arises when the Flatpak client extracts OCI archives without validating the destination paths, allowing an attacker who controls the OCI registry to supply file paths that map to arbitrary host files.

The CVSS score of 6.5 indicates moderate severity, but the impact is high for root‑running installations because the attacker can read critical files. The EPSS score is not available, and the vulnerability is not listed in CISA KEV. Exploitation requires the attacker to provide a malicious OCI registry entry and a user to install or update a Flatpak application from that registry. For normal user installations, the risk is lower, but for system‑wide, privileged installs the compromise can lead to credential theft.