Unity Linux 20.1050a Security Update: kernel (UTSA-2026-100582)

critical Nessus Plugin ID 336852

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-2026-100582 advisory.

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

tunnels: do not assume transport header in iptunnel_pmtud_check_icmp()

In some cases, iptunnel_pmtud_check_icmp() can be called while skb transport header is not set.

This triggers an out-of-bound access, because (typeof(skb->transport_header))~0U is 65535.

Access the icmp header based on IPv4 network header, after making sure icmp->type is present in skb linear part.

Note that iptunnel_pmtud_check_icmpv6()) is fine.

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-2026-63992

http://www.nessus.org/u?635bc9e6

http://www.nessus.org/u?cbc8a33d

Plugin Details

Severity: Critical

ID: 336852

File Name: unity_linux_UTSA-2026-100582.nasl

Version: 1.1

Type: Local

Published: 8/17/2026

Updated: 8/17/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.53

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7

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

CVSS Score Source: CVE-2026-63992

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 7.9

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/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: 8/13/2026

Vulnerability Publication Date: 7/7/2026

Reference Information

CVE: CVE-2026-63992