Flatpak: flatpak: world-writable temporary child repositories in system-helper cache path
Published Sep 28, 2026
3.9
LOWCVSS 3.1
EPSS 0.11%
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.
Affected products
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||
|---|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | affected |
| |||
| Red Hat | Red Hat Enterprise Linux 7 | affected |
| |||
| Red Hat | Red Hat Enterprise Linux 8 | affected |
| |||
| Red Hat | Red Hat Enterprise Linux 9 | affected |
|
No data.
No data.
Red Hat Enterprise Linux 10
flatpak
Fix deferred
Red Hat Enterprise Linux 7
flatpak
Fix deferred
Red Hat Enterprise Linux 8
flatpak
Fix deferred
Red Hat Enterprise Linux 9
flatpak
Fix deferred
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | flatpak | Fix deferred | n/a |
| Red Hat Enterprise Linux 7 | flatpak | Fix deferred | n/a |
| Red Hat Enterprise Linux 8 | flatpak | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | flatpak | Fix deferred | n/a |
No package ranges for this CVE.
Remediation
Vendor solution
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.
Red Hat statement
Red Hat estimates the CVSSv3.1 vector of CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:L from provided CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N. Requires user interaction and scope remains unchanged.
Red Hat mitigation
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.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:N/A:L
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
CISA SSVC (Vulnrichment)
Stakeholder-Specific Vulnerability Categorization from CISA ADP.
Exploitation
NoneAutomatable
NoTechnical Impact
PartialDecision
n/aAssessed Sep 30, 2026 · SSVC 2.0.3
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 1, 2026.
Score over time
Not enough EPSS history yet for a chart. At least two recorded scores are needed.
Percentile over time
Not enough EPSS history yet for a chart. At least two recorded scores are needed.
References (5)
- https://access.redhat.com/security/cve/CVE-2026-97026 vdb-entryx_refsource_REDHATVendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2542637 issue-trackingx_refsource_REDHATIssue Tracking
- https://github.com/flatpak/flatpak/security/advisories/GHSA-r9w3-qx54-qvc8
- https://nvd.nist.gov/vuln/detail/CVE-2026-97026
- https://www.cve.org/CVERecord?id=CVE-2026-97026
| Link | Providers | Tags |
|---|---|---|
| https://access.redhat.com/security/cve/CVE-2026-97026 | vdb-entryx_refsource_REDHATVendor Advisory | |
| https://bugzilla.redhat.com/show_bug.cgi?id=2542637 | issue-trackingx_refsource_REDHATIssue Tracking | |
| https://github.com/flatpak/flatpak/security/advisories/GHSA-r9w3-qx54-qvc8 | ||
| https://nvd.nist.gov/vuln/detail/CVE-2026-97026 | ||
| https://www.cve.org/CVERecord?id=CVE-2026-97026 |
Change history (0)
No recorded changes yet.