Creation of Temporary File With Insecure Permissions in Flatpak - CVE-2026-97026
Published: September 28, 2026
Vulnerability identifier: #VU152569
CSH Severity: Low
CVSS v4: 4.6 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-97026
CWE-ID: CWE-378
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to insecure temporary directory permissions in temporary child repositories under the system-helper cache path when installing apps. A local user can modify the temporary directory to cause a denial of service.
Exploitation is limited to multi-user systems where the user's umask permits other users to write to the cache directory.
Affected software
Flatpak
How to mitigate CVE-2026-97026
Install security update from vendor's website.
Flatpak - update to 1.18.4