Linux Distros Unpatched Vulnerability : CVE-2026-90616

high Nessus Plugin ID 345465

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

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

- In Flatpak before 1.18.1, a malicious sandboxed app can obtain arbitrary read and write access to files on the host, which can be escalated to arbitrary code execution on the host, a different vulnerability than CVE-2026-76925. Flatpak creates a few app data directories (e.g., /var/cache, /var/data, /var/config, and /var/tmp) in every sandbox on every app launch where, in some cases, components of the path are attacker- controlled. Missing symlink protection can redirect the directories. Some of these directories are bind- mounted by Flatpak by passing the path (e.g., /home/user/.var/app/APP_ID/cache/tmp), which contains attacker-controlled directories (tmp) to bwrap --bind SRC DST. bwrap passes the path on to the kernel, which then follows symlinks. A malicious symlink can point to arbitrary locations on the host and it will become mounted inside the sandbox. (CVE-2026-90616)

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

Solution

There is no known solution at this time.

See Also

https://access.redhat.com/security/cve/cve-2026-90616

https://security-tracker.debian.org/tracker/CVE-2026-90616

https://ubuntu.com/security/CVE-2026-90616

Plugin Details

Severity: High

ID: 345465

File Name: unpatched_CVE_2026_90616.nasl

Version: 1.4

Type: Local

Agent: unix

Family: Misc.

Published: 9/13/2026

Updated: 9/16/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.53

CVSS v2

Risk Factor: Medium

Base Score: 6.2

Temporal Score: 5.3

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

CVSS Score Source: CVE-2026-90616

CVSS v3

Risk Factor: High

Base Score: 7.4

Temporal Score: 6.8

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

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

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, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:centos:centos:7, cpe:/o:centos:centos:8, cpe:/o:debian:debian_linux:12.0, cpe:/o:redhat:enterprise_linux:10, cpe:/o:redhat:enterprise_linux:7, cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:canonical:ubuntu_linux:flatpak, p-cpe:/a:centos:centos:flatpak-builder, p-cpe:/a:centos:centos:flatpak-devel, p-cpe:/a:centos:centos:flatpak-libs, p-cpe:/a:centos:centos:flatpak-selinux, p-cpe:/a:centos:centos:flatpak-session-helper, p-cpe:/a:centos:centos:flatpak, p-cpe:/a:debian:debian_linux:flatpak, p-cpe:/a:redhat:enterprise_linux:flatpak-builder, p-cpe:/a:redhat:enterprise_linux:flatpak-devel, p-cpe:/a:redhat:enterprise_linux:flatpak-libs, p-cpe:/a:redhat:enterprise_linux:flatpak-selinux, p-cpe:/a:redhat:enterprise_linux:flatpak-session-helper, p-cpe:/a:redhat:enterprise_linux:flatpak

Required KB Items: Host/cpu, Host/local_checks_enabled, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 9/12/2026

Reference Information

CVE: CVE-2026-90616