Unity Linux 20.1050e Security Update: kernel (UTSA-2026-102028)

medium Nessus Plugin ID 338509

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-2026-102028 advisory.

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

tcp: restrict SO_ATTACH_FILTER to priv users

This patch restricts the use of SO_ATTACH_FILTER (cBPF) on TCP sockets to users with CAP_NET_ADMIN capability.

This blocks potential side-channel attack where an unprivileged application attaches a filter to leak TCP sequence/acknowledgment numbers.

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-2026-53236

http://www.nessus.org/u?2eb07ad5

http://www.nessus.org/u?9fb72997

Plugin Details

Severity: Medium

ID: 338509

File Name: unity_linux_UTSA-2026-102028.nasl

Version: 1.1

Type: Local

Published: 8/21/2026

Updated: 8/21/2026

Supported Sensors: Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.72

CVSS v2

Risk Factor: Medium

Base Score: 4.6

Temporal Score: 3.4

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

CVSS Score Source: CVE-2026-53236

CVSS v3

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 4.8

Vector: CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/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: 8/17/2026

Vulnerability Publication Date: 6/25/2026

Reference Information

CVE: CVE-2026-53236