CVE-2026-97026

Flatpak: flatpak: world-writable temporary child repositories in system-helper cache path

Published Sep 28, 2026 CVSS 3.1 · 3.9 Low EPSS < 1% KEV · Not listed
Description
Flatpak creates temporary child repository directories under the user cache with world-writable permissions (0777). On multi-user systems with a permissive umask, other local users could read or modify the temporary directory used while installing apps or runtimes, potentially causing installation failures (denial of service); tampered content would fail signature/digest verification rather than being trusted.

Remediation

Vendor Workaround

Set a umask that does not allow other users to write to the cache directory, for example: umask 022. Note that a umask that does not allow read/exec access by all (for example 027 or 077) will prevent the flatpak-system-helper from reading the temporary directory directly, resulting in falling back to copying the repository inefficiently, with a warning.

Tracking

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Advisories

Source ID Title
Debian DSA Debian DSA DSA-6524-1 flatpak security update
History
Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Els
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Flatpak
Flatpak flatpak
Vendors & Products Flatpak
Flatpak flatpak
Type Values Removed Values Added
Description Flatpak creates temporary child repository directories under the user cache with world-writable permissions (0777). On multi-user systems with a permissive umask, other local users could read or modify the temporary directory used while installing apps or runtimes, potentially causing installation failures (denial of service); tampered content would fail signature/digest verification rather than being trusted.
Title Flatpak: flatpak: world-writable temporary child repositories in system-helper cache path
First Time appeared Redhat
Redhat enterprise Linux
Weaknesses CWE-378
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
References
Metrics cvssV3_1

{'score': 3.9, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:L'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 6, 2026, 8:01 PM
Reserved
Sep 23, 2026, 9:11 PM
Status
Awaiting Analysis
Published
Sep 28, 2026, 9:17 PM
Modified
Nov 6, 2026, 8:17 PM
Severity
Low
Public date
Sep 28, 2026, 1:28 PM