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

> A malicious Flatpak app can terminate unsandboxed processes sharing its process group, causing denial of service on the host system.

- **Severity:** Medium 5.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** Yes
- **Published:** 29 Sep 2026
- **Updated:** 29 Sep 2026
- **Also known as:** DEBIAN-CVE-2026-97029, UBUNTU-CVE-2026-97029

## What is CVE-2026-97029?

CVE-2026-97029 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 29 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

### Official description

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.

Weakness: CWE-653 (Improper Isolation or Compartmentalization)

## Which versions are affected by CVE-2026-97029?


## How do I fix CVE-2026-97029?

Apply the vendor's patch.

## Is CVE-2026-97029 being exploited?

There is no known exploitation of CVE-2026-97029 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-97029 and fix it if it is affected.

What it is: CVE-2026-97029 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, published on 29 Sep 2026. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.
Exploitation: There is no known exploitation of CVE-2026-97029 in the wild and no public exploit code.

Affected product: Red Hat Enterprise Linux 10. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-97029/ (Markdown: https://insights.sbomify.com/CVE-2026-97029/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-97029
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-97029
- OSV: https://osv.dev/vulnerability/CVE-2026-97029

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-97029/
Summaries are generated and may contain mistakes; the official description above is the record.