Unity Linux 20.1070a Security Update: kernel (UTSA-2026-143107)

critical Nessus Plugin ID 370584

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-2026-143107 advisory.

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

netfilter: ip6t_eui64: reject invalid MAC header for all packets

`eui64_mt6()` derives a modified EUI-64 from the Ethernet source address and compares it with the low 64 bits of the IPv6 source address.

The existing guard only rejects an invalid MAC header when `par->fragoff != 0`. For packets with `par->fragoff == 0`, `eui64_mt6()` can still reach `eth_hdr(skb)` even when the MAC header is not valid.

Fix this by removing the `par->fragoff != 0` condition so that packets with an invalid MAC header are rejected before accessing `eth_hdr(skb)`.

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.

See Also

https://nvd.nist.gov/vuln/detail/CVE-2026-31685

https://security-tracker.debian.org/tracker/CVE-2026-31685

http://www.nessus.org/u?00057748

http://www.nessus.org/u?19399dce

http://www.nessus.org/u?a19eda69

http://www.nessus.org/u?b42fa1bd

http://www.nessus.org/u?b5af0f72

http://www.nessus.org/u?b6863122

http://www.nessus.org/u?c119e9ca

http://www.nessus.org/u?c2deb7fe

http://www.nessus.org/u?e05592ed

http://www.nessus.org/u?f754ac1d

Plugin Details

Severity: Critical

ID: 370584

File Name: unity_linux_UTSA-2026-143107.nasl

Version: 1.1

Type: Local

Published: 10/22/2026

Updated: 10/22/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.5

Percentile: 57.48

CVSS v2

Risk Factor: High

Base Score: 9.7

Temporal Score: 7.2

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

CVSS Score Source: CVE-2026-31685

CVSS v3

Risk Factor: Critical

Base Score: 9.4

Temporal Score: 8.2

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

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: 10/23/2026

Vulnerability Publication Date: 4/25/2026

Reference Information

CVE: CVE-2026-31685