# CVE-2026-96279: Flatpak arbitrary file disclosure via OCI registry hardlink

Source: https://junglewise.ai/threats/cve-2026-96279-a-malicious-oci-registry-can-hardlink-arbitrary-host-files-into  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-27. Updated: 2026-09-27  
License: CC BY 4.0 with a link back

CVE-2026-96279 · Severity: medium · CVSS 6.5 · Published 2026-09-27

Flatpak, a system for installing and running containerized applications, can be tricked by a malicious OCI registry into copying sensitive files from the host system into an application's sandbox during installation or updates. When a system-wide installation runs with root privileges, an attacker can gain read access to highly sensitive files like /etc/shadow, compromising system security and user credentials.

Technologies: [Flatpak](https://junglewise.ai/threats/technologies/flatpak). Vendors: [Flatpak](https://junglewise.ai/threats/vendors/flatpak).

## Quick answers

**Is CVE-2026-96279 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-96279 being exploited in the wild.

**How severe is CVE-2026-96279?** Medium severity, with a CVSS score of 6.5, published 27 September 2026.

**Which products and versions are affected?** Flatpak Flatpak.

**Is there a fix for CVE-2026-96279?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-96279 attacked?** It is in a network appliance.

**Am I affected by CVE-2026-96279?** Check whether you run Flatpak. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in Flatpak's OCI archive extraction logic, which fails to properly rebase hardlink targets before processing. While the extractor correctly validates and rebases archive entry pathnames and rejects path traversal attempts with "..", it does not validate hardlink targets themselves, allowing an attacker to craft archive entries with absolute hardlink targets (e.g., /etc/shadow) that libarchive will directly hardlink into the extraction directory. On system-wide installations running as root, this exposes any root-owned file to the installing user; on user installs, hardlinked files become readable to that user. The vulnerability requires user interaction to trigger the malicious app installation and affects only OCI-based remotes, not the default OSTree transport.

## Affected products

- Flatpak Flatpak

## Timeline

- 2026-09-27: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-96279](https://access.redhat.com/security/cve/CVE-2026-96279)

## Related threats

- [Flatpak path traversal in system-helper via crafted architecture name](https://junglewise.ai/threats/cve-2026-92162-flatpak-is-a-system-for-building-distributing-and-running)
- [Flatpak process ID namespace isolation bypass](https://junglewise.ai/threats/cve-2026-97029-flatpak-s-process-id-namespace-separation-does-not-prevent-a)
- [Flatpak path traversal in files/etc directory during app deployment](https://junglewise.ai/threats/cve-2026-97024-a-path-traversal-vulnerability-in-flatpak-s-handling-of-the-files)
- [Flatpak path traversal in export/bin directory handling](https://junglewise.ai/threats/cve-2026-97023-a-path-traversal-vulnerability-in-flatpak-s-handling-of-the)
- [Flatpak heap buffer overflow in OCI delta stream parser](https://junglewise.ai/threats/cve-2026-96280-the-oci-delta-stream-parser-read-sizes-as-guint64-but-passed-them)