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.

The remote Fedora 44 host has a package installed that is affected by multiple vulnerabilities as referenced in the FEDORA-2026-7a31054ed6 advisory.

    Update to 1.18.4

Tenable has extracted the preceding description block directly from the Fedora security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - 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. (CVE-2026-97029)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote Debian 13 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-6524 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-6524-1                   security@debian.org     https://www.debian.org/security/                       Moritz Muehlenhoff     September 28, 2026                    https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : flatpak     CVE ID         : CVE-2026-90616 CVE-2026-92162 CVE-2026-97023 CVE-2026-97024                      CVE-2026-97025 CVE-2026-97026 CVE-2026-97027 CVE-2026-97029

    Multiple security vulnerabilities were discovered in Flatpak, an     application deployment framework for desktop apps, which could result in     denial service via malicious applications or information disclosure.

    For the stable distribution (trixie), these problems have been fixed in     version 1.16.6-1~deb13u3.

    We recommend that you upgrade your flatpak packages.

    For the detailed security status of flatpak please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/flatpak

    Further information about Debian Security Advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://www.debian.org/security/

    Mailing list: debian-security-announce@lists.debian.org

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Type	Severity
362886	Fedora 44 : flatpak (2026-7a31054ed6)	Nessus	Fedora Local Security Checks	Local	high
351009	Linux Distros Unpatched Vulnerability : CVE-2026-97029	Nessus	Misc.	Local	medium
350953	Debian dsa-6524 : flatpak - security update	Nessus	Debian Local Security Checks	Local	high

Detections

Analytics

CVE-2026-97029

medium

Tenable Plugins

high

medium

high