CVE-2026-34078
Medium
Elevated severity or exploit probability.
CVSS base
10.0
CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
EPSS — probability of exploitation (30 days)
0.9%
57.8th percentile
CISA KEV
Not listed
Weakness / dates
CWE-59
Published 2026-04-07 · modified 2026-07-24
Description
Flatpak is a Linux application sandboxing and distribution framework. Prior to 1.16.4, the Flatpak portal accepts paths in the sandbox-expose options which can be app-controlled symlinks pointing at arbitrary paths. Flatpak run mounts the resolved host path in the sandbox. This gives apps access to all host files and can be used as a primitive to gain code execution in the host context. This vulnerability is fixed in 1.16.4.
Affected
References
- https://github.com/flatpak/flatpak/security/advisories/GHSA-cc2q-qc34-jprg
- http://www.openwall.com/lists/oss-security/2026/04/09/8
- http://www.openwall.com/lists/oss-security/2026/04/10/14
- https://access.redhat.com/errata/RHSA-2026:21755
- https://access.redhat.com/errata/RHSA-2026:21756
- https://access.redhat.com/errata/RHSA-2026:21757
- https://access.redhat.com/errata/RHSA-2026:23417
- https://access.redhat.com/errata/RHSA-2026:23418
- https://access.redhat.com/errata/RHSA-2026:23419
- https://access.redhat.com/errata/RHSA-2026:23420
- https://access.redhat.com/errata/RHSA-2026:25068
- https://access.redhat.com/errata/RHSA-2026:25381
- https://access.redhat.com/errata/RHSA-2026:30901
- https://access.redhat.com/errata/RHSA-2026:35843
- https://access.redhat.com/security/cve/CVE-2026-34078
- https://bugzilla.redhat.com/show_bug.cgi?id=2456276
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34078.json