CVE-2026-97025 in Red Hat
Summary
by MITRE • 09/29/2026
Flatpak writes the OCI repository authentication token with world-readable permissions (0644) in the system-helper's cache directory, allowing other local users on a multi-user system to read the token and impersonate the authenticated user against the OCI repository. Only OCI-based sources (e.g. as used by Fedora) are affected; libostree-based sources such as Flathub are not.
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Analysis
by VulDB Data Team • 09/29/2026
The vulnerability involves an improper permission setting on authentication credentials stored within a Flatpak system helper cache directory, specifically affecting systems utilizing Open Container Initiative repositories rather than traditional OSTree sources like Flathub. When the Flatpak daemon authenticates with an OCI-based repository to fetch application metadata or updates, it stores the resulting access token in a local file for caching purposes. The critical flaw lies in the fact that this file is created with world-readable permissions, specifically octal mode 0644. This configuration grants read access to any user account on the system, including unprivileged and potentially malicious actors who share the same host environment as the authenticated Flatpak instance.
From a technical perspective, this represents a classic case of insecure default file permissions leading to unauthorized information disclosure. The authentication token serves as a credential that proves identity to the remote OCI registry. By storing this sensitive material in a location accessible to all local users without adequate restriction, the system fails to enforce proper isolation between user contexts. An attacker with any level of shell access on the multi-user machine can simply read the cached file and extract the bearer token or API key embedded within it. This action bypasses the need for direct exploitation of application logic flaws, relying instead on poor operating system-level security hygiene regarding sensitive data storage.
The operational impact of this vulnerability is significant in shared computing environments such as corporate workstations, university labs, or cloud instances where multiple users interact with the same Flatpak installation. Once an attacker obtains the token, they can impersonate the original user when communicating with the OCI repository. This allows the adversary to perform actions that require authentication, potentially including downloading private applications, accessing restricted metadata, or in more complex scenarios involving write access tokens, pushing malicious content into repositories managed by the victim. The scope of damage is limited strictly to OCI-based sources; systems relying solely on libostree protocols for distribution channels like Flathub remain unaffected because they do not utilize this specific caching mechanism with these permissions.
This vulnerability aligns closely with CWE-732, which describes improper permission assignment for critical resources, and falls under the ATT&CK technique of T1552.004, specifically Unsecured Credentials in a Local File. The failure to restrict file access violates fundamental principles of least privilege and secure configuration management. To mitigate this risk, system administrators should ensure that Flatpak is updated to versions where the cache directory permissions are corrected to be restrictive, typically 0600 or 0700, ensuring only the owning user can read or write the authentication data. Additionally, users on multi-tenant systems should monitor for updates from their distribution maintainers who may have backported patches addressing this permission misconfiguration in older Flatpak releases.