# CVE-2026-97029: Flatpak: flatpak: sandboxed app can signal unsandboxed processes in the same process group

Status: published. Published: 2026-09-29. Updated: 2026-11-06.

Flatpak's process ID namespace separation does not prevent a sandboxed app's kill(0, signal) or killpg(0, signal) calls from reaching processes outside the sandbox that share the same process group. A malicious or compromised Flatpak app can use this to cause denial of service by terminating processes outside its sandbox, such as the desktop shell.

## Remediation

- workaround: Run Flatpak apps in a new session (setsid flatpak run ... or setsid() in the parent) or a new process group (setpgid (0, 0) in the parent), or avoid running untrusted Flatpak apps. (source: CNA: redhat)

## Affected products and versions

- Red Hat / Red Hat Enterprise Linux 10 (flatpak): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (flatpak): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (flatpak): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (flatpak): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 5.7 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.24% as of 2026-11-05; percentile 15.79%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-653

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/security/cve/CVE-2026-97029 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2542698 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://github.com/flatpak/flatpak/security/advisories/GHSA-f3p8-vr7v-gxf2 (CNA: redhat)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-97029; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-97029; retrieved 2026-11-06; source updated Not reported

Revision: a2477cf76b27e0596da5490825cd5c5a6122e4d66f8aea7e34af9b29061270af

Canonical: https://y2.dev/cve/CVE-2026-97029

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