Unity Linux 20.1050a Security Update: kernel (UTSA-2026-104599)

critical Nessus Plugin ID 339559

Synopsis

The Unity Linux host is missing one or more security updates.

Description

The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the UTSA-2026-104599 advisory.

In the Linux kernel, the following vulnerability has been resolved:

ipv4: fib: Don't ignore error route in local/main tables.

When CONFIG_IP_MULTIPLE_TABLES is enabled but no rule is added, fib_lookup() performs route lookup directly on two tables.

Since the first lookup does not properly bail out, the result of an error route in the merged local/main table could be overwritten by another route in the default table:

# unshare -n # ip link set lo up # ip route add 192.168.0.0/24 dev lo table 253 # ip route add unreachable 192.168.0.0/24 # ip route get 192.168.0.1 192.168.0.1 dev lo table default uid 0 cache <local>

Once a random rule is added, the error route is respected:

# ip rule add table 0 # ip rule del table 0 # ip route get 192.168.0.1 RTNETLINK answers: No route to host

Let's fix the inconsistent behaviour.

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

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

Solution

Update the affected kernel package.

Plugin Details

Severity: Critical

ID: 339559

File Name: unity_linux_UTSA-2026-104599.nasl

Version: 1.1

Type: Local

Family: Unity Linux Local Security Checks

Published: 8/26/2026

Updated: 8/26/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.8

Percentile: 57.82

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

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

CVSS Score Source: CVE-2026-72421

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:N

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

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/cpu, Host/UOS-Server/release, Host/UOS-Server/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 8/25/2026

Vulnerability Publication Date: 8/11/2026

Reference Information

CVE: CVE-2026-72421

Detections

Analytics