# CVE-2026-97029: Flatpak process ID namespace isolation bypass

Source: https://junglewise.ai/threats/cve-2026-97029-flatpak-s-process-id-namespace-separation-does-not-prevent-a  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-29. Updated: 2026-09-29  
License: CC BY 4.0 with a link back

CVE-2026-97029 · Severity: medium · CVSS 5.7 · Published 2026-09-29

Flatpak is a containerization system that isolates applications from the host system. A flaw in its process isolation allows a malicious or compromised sandboxed app to send signals that terminate processes outside its sandbox, including critical system components like the desktop shell. An attacker can cause denial of service by crashing the user's entire desktop session.

Technologies: [Flatpak](https://junglewise.ai/threats/technologies/flatpak). Vendors: [Flatpak](https://junglewise.ai/threats/vendors/flatpak).

## Quick answers

**Is CVE-2026-97029 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-97029 being exploited in the wild.

**How severe is CVE-2026-97029?** Medium severity, with a CVSS score of 5.7, published 29 September 2026.

**Which products and versions are affected?** Flatpak Flatpak.

**Is there a fix for CVE-2026-97029?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-97029 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2026-97029?** Check whether you run Flatpak. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability exists in Flatpak's process ID namespace implementation, where kill(0, signal) and killpg(0, signal) calls from a sandboxed application can reach processes outside the sandbox that share the same process group. This is a compartmentalization bypass that requires the victim to install and run a malicious Flatpak app; the signal leak is then triggered automatically. The impact is availability denial of service against host processes.

## Affected products

- Flatpak Flatpak

## Timeline

- 2026-09-29: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-97029](https://access.redhat.com/security/cve/CVE-2026-97029)

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