---
id: CVE-2026-42965
title: A flaw was found in the OpenShift Router
summary: >-
  A flaw was found in the OpenShift Router. A user with EndpointSlice write
  access can exploit this vulnerability by creating a Service backed by an FQDN
  (Fully Qualified Domain Name) EndpointSlice that resolves to a cloud metadata
  endpoin…
severity: high
cvss: 7.7
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N'
cwe:
  - CWE-918
vendor: redhat
product: openshift_container_platform
affected:
  - openshift_container_platform = 4.0
  - openshift_router
patched:
  - openshift_container_platform 4.19
  - openshift_container_platform 4.21
  - openshift_container_platform 4.22
  - openshift_container_platform 4.2
published: '2026-05-29'
updated: '2026-09-21'
sourceUpdated: '2026-09-21T12:17:13.497'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-42965'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:54583'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:54602'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:54770'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:57408'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:65852'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-42965'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2483184'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/errata/RHSA-2026:54583'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:54602'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:54770'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/errata/RHSA-2026:57408'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://access.redhat.com/security/cve/CVE-2026-42965'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2483184'
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42965.json
    label: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-42965'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-42965'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00269
epssPercentile: 0.19338
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-05-30T02:24:09.743182Z'
ingestedAt: '2026-08-23T11:46:47.892Z'
---

## Overview

A flaw was found in the OpenShift Router. A user with EndpointSlice write access can exploit this vulnerability by creating a Service backed by an FQDN (Fully Qualified Domain Name) EndpointSlice that resolves to a cloud metadata endpoint. This allows the router to proxy requests to the cloud metadata endpoint, leading to the disclosure of instance credentials and other sensitive metadata. This bypasses previous security measures for validating IP addresses.

## Affected

- `openshift_container_platform = 4.0`
- `openshift_router`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

## Vendor advisories

- **RHSA-2026:57408** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.19 · released 2026-08-26 · [advisory](https://access.redhat.com/errata/RHSA-2026:57408)
- **RHSA-2026:54602** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.21 · released 2026-08-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:54602)
- **RHSA-2026:54770** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.22 · released 2026-08-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:54770)
- **RHSA-2026:54583** · Red Hat · fixed in: Red Hat OpenShift Container Platform 4.2 · released 2026-08-18 · [advisory](https://access.redhat.com/errata/RHSA-2026:54583)
- **Red Hat VEX** · Important · affected: Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat OpenShift Container Platform 4 · updated 2026-09-09 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42965.json)