Detections
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Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS : Flatpak vulnerabilities (USN-8741-1)

critical Nessus Plugin ID 344634

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8741-1 advisory.

 It was discovered that Flatpak did not properly validate paths in sandbox-expose options. A malicious or compromised Flatpak app could use app-controlled symlinks to access arbitrary host files and gain code execution in the host context. This issue was addressed in Ubuntu Ubuntu 20.04 LTS, Ubuntu 22.04 LTS and Ubuntu 24.04 LTS. (CVE-2026-34078)

 It was discovered that Flatpak did not properly validate paths when

 removing outdated ld.so cache files. A malicious or compromised Flatpak app could use this issue to delete arbitrary files on the host.

 (CVE-2026-34079)

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

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

Solution

Update the affected packages.

See Also

https://ubuntu.com/security/notices/USN-8741-1

Plugin Details

Severity: Critical

ID: 344634

File Name: ubuntu_USN-8741-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 9/10/2026

Updated: 9/10/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.8

Percentile: 99.33

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

CVSS Score Source: CVE-2026-34078

CVSS v3

Risk Factor: Critical

Base Score: 10

Temporal Score: 8.7

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

CVSS v4

Risk Factor: Critical

Base Score: 9.3

Threat Score: 8.1

Threat Vector: CVSS:4.0/E:U

Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:flatpak-tests, p-cpe:/a:canonical:ubuntu_linux:flatpak, p-cpe:/a:canonical:ubuntu_linux:gir1.2-flatpak-1.0, p-cpe:/a:canonical:ubuntu_linux:libflatpak0

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Ease: No known exploits are available

Patch Publication Date: 9/10/2026

Vulnerability Publication Date: 4/7/2026

Reference Information

CVE: CVE-2026-34078, CVE-2026-34079

IAVA: 2026-A-0317

USN: 8741-1