RHCOS 4 : OpenShift Container Platform 4.20.34 (RHSA-2026:54580)

high Nessus Plugin ID 337666

Synopsis

The remote Red Hat CoreOS host is missing a security update for OpenShift Container Platform 4.20.34.

Description

The remote Red Hat Enterprise Linux CoreOS 4 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2026:54580 advisory.

- golang.org/x/net/idna: golang: net/http: golang.org/x/net/idna: Privilege escalation via incorrect Punycode label processing (CVE-2026-39821)

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 RHCOS OpenShift Container Platform 4.20.34 packages based on the guidance in RHSA-2026:54580.

Plugin Details

Severity: High

ID: 337666

File Name: rhcos-RHSA-2026-54580.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 8/18/2026

Updated: 8/18/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.8

Percentile: 57.83

Vendor

Vendor Severity: Important

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-2026-39821

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.1

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

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

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:8:coreos, cpe:/o:redhat:enterprise_linux:9:coreos, p-cpe:/a:redhat:enterprise_linux:openshift-clients-redistributable, p-cpe:/a:redhat:enterprise_linux:openshift-clients

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: 8/18/2026

Vulnerability Publication Date: 5/12/2026

Reference Information

CVE: CVE-2026-39821

CWE: 1289

RHSA: 2026:54580

Detections

Analytics