RHCOS 4 : OpenShift Container Platform 4.18.43 (RHSA-2026:21655)

high Nessus Plugin ID 319505

Synopsis

The remote Red Hat CoreOS host is missing one or more security updates for OpenShift Container Platform 4.18.43.

Description

The remote Red Hat Enterprise Linux CoreOS 4 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:21655 advisory.

- net/url: Incorrect parsing of IPv6 host literals in net/url (CVE-2026-25679)

- crypto/x509: crypto/tls: golang: Go: Denial of Service vulnerability in certificate chain building (CVE-2026-32280)

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 OpenShift Container Platform 4.18.43 packages based on the guidance in RHSA-2026:21655.

See Also

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

https://bugzilla.redhat.com/show_bug.cgi?id=2445356

https://bugzilla.redhat.com/show_bug.cgi?id=2456339

http://www.nessus.org/u?87111782

https://access.redhat.com/errata/RHSA-2026:21655

Plugin Details

Severity: High

ID: 319505

File Name: rhcos-RHSA-2026-21655.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 6/6/2026

Updated: 6/6/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: Low

Base Score: 2.1

Temporal Score: 1.6

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

CVSS Score Source: CVE-2026-25679

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

CVSS Score Source: CVE-2026-32280

Vulnerability Information

CPE: p-cpe:/a:redhat:enterprise_linux:podman-catatonit, p-cpe:/a:redhat:enterprise_linux:podman-gvproxy, p-cpe:/a:redhat:enterprise_linux:podman-plugins, p-cpe:/a:redhat:enterprise_linux:podman-tests, p-cpe:/a:redhat:enterprise_linux:containernetworking-plugins, p-cpe:/a:redhat:enterprise_linux:runc, cpe:/o:redhat:enterprise_linux:9:coreos, p-cpe:/a:redhat:enterprise_linux:skopeo-tests, p-cpe:/a:redhat:enterprise_linux:skopeo, cpe:/o:redhat:enterprise_linux:8:coreos, p-cpe:/a:redhat:enterprise_linux:podman-docker, p-cpe:/a:redhat:enterprise_linux:podman-remote, p-cpe:/a:redhat:enterprise_linux:podman

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: 6/3/2026

Vulnerability Publication Date: 3/5/2026

Reference Information

CVE: CVE-2026-25679, CVE-2026-32280

CWE: 1286, 770

RHSA: 2026:21655