RHCOS 4 : Red Hat build of MicroShift 4.18.54 (RHSA-2026:57914)

high Nessus Plugin ID 339919

Synopsis

The remote Red Hat CoreOS host is missing one or more security updates for Red Hat build of MicroShift 4.18.54.

Description

The remote Red Hat Enterprise Linux CoreOS 4 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:57914 advisory.

- net/mail: golang: Go net/mail: Denial of Service via crafted email inputs (CVE-2026-39820)

- net/mail: golang: net/mail: Denial of Service via pathological email address parsing (CVE-2026-42499)

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

Solution

Update the RHCOS Red Hat build of MicroShift 4.18.54 package based on the guidance in RHSA-2026:57914.

See Also

https://access.redhat.com/errata/RHSA-2026:57914

https://access.redhat.com/security/updates/classification/#important

https://bugzilla.redhat.com/show_bug.cgi?id=2467809

https://bugzilla.redhat.com/show_bug.cgi?id=2467820

http://www.nessus.org/u?5041ea96

Plugin Details

Severity: High

ID: 339919

File Name: rhcos-RHSA-2026-57914.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 8/26/2026

Updated: 8/26/2026

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

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.73

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

CVSS Score Source: CVE-2026-39820

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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

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

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:9:coreos, p-cpe:/a:redhat:enterprise_linux:microshift-gateway-api-release-info, p-cpe:/a:redhat:enterprise_linux:microshift-gateway-api, p-cpe:/a:redhat:enterprise_linux:microshift-greenboot, p-cpe:/a:redhat:enterprise_linux:microshift-low-latency, p-cpe:/a:redhat:enterprise_linux:microshift-multus-release-info, p-cpe:/a:redhat:enterprise_linux:microshift-multus, p-cpe:/a:redhat:enterprise_linux:microshift-networking, p-cpe:/a:redhat:enterprise_linux:microshift-olm-release-info, p-cpe:/a:redhat:enterprise_linux:microshift-olm, p-cpe:/a:redhat:enterprise_linux:microshift-release-info, p-cpe:/a:redhat:enterprise_linux:microshift-selinux, p-cpe:/a:redhat:enterprise_linux:microshift

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

Exploit Ease: No known exploits are available

Patch Publication Date: 8/26/2026

Vulnerability Publication Date: 5/7/2026

Reference Information

CVE: CVE-2026-39820, CVE-2026-42499

CWE: 1046, 606

RHSA: 2026:57914