# CVE-2026-42965: Openshift/router: openshift/router: cloud metadata ssrf via fqdn-typed endpointslice bypasses destination validation

Status: published. Published: 2026-05-29. Updated: 2026-11-04.

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.

## Remediation

- fix: RHSA-2026:57408: Red Hat OpenShift Container Platform 4.19

RHSA-2026:54583: Red Hat OpenShift Container Platform 4.20

RHSA-2026:54602: Red Hat OpenShift Container Platform 4.21

RHSA-2026:54770: Red Hat OpenShift Container Platform 4.22 (source: ADP: redhat-SADP)

## Affected products and versions

- Red Hat / Red Hat OpenShift Container Platform 4.17 (openshift4/ose-haproxy-router-rhel9): ≥ 1789938693; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4.18 (openshift4/ose-haproxy-router-rhel9): ≥ 1788578875; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4.19 (openshift4/ose-haproxy-router-rhel9): ≥ 1786771399; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4.20 (openshift4/ose-haproxy-router-rhel9): ≥ 1786496552; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4.21 (openshift4/ose-haproxy-router-rhel9): ≥ 1786498169; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4.22 (openshift4/ose-haproxy-router-rhel9): ≥ 1786584196; < * (unaffected, rpm). Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift4/ose-haproxy-router): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift5/ose-haproxy-router-rhel9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4.19 (openshift4/ose-haproxy-router-rhel9): ≥ 1786771399; < * (unaffected, rpm). Source: ADP: redhat-SADP
- Red Hat / Red Hat OpenShift Container Platform 4.20 (openshift4/ose-haproxy-router-rhel9): ≥ 1786496552; < * (unaffected, rpm). Source: ADP: redhat-SADP
- Red Hat / Red Hat OpenShift Container Platform 4.21 (openshift4/ose-haproxy-router-rhel9): ≥ 1786498169; < * (unaffected, rpm). Source: ADP: redhat-SADP
- Red Hat / Red Hat OpenShift Container Platform 4.22 (openshift4/ose-haproxy-router-rhel9): ≥ 1786584196; < * (unaffected, rpm). Source: ADP: redhat-SADP
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift4/ose-haproxy-router): Version range not reported. Source: ADP: redhat-SADP

## NVD configuration conditions

Affected CPE matches depend on the following AND/OR and negation conditions:

```json
[
  {
    "negate": false,
    "nodes": [
      {
        "cpeMatch": [
          {
            "criteria": "cpe:2.3:a:redhat:openshift_container_platform:4.0:*:*:*:*:*:*:*",
            "vulnerable": true
          },
          {
            "criteria": "cpe:2.3:a:redhat:openshift_router:-:*:*:*:*:*:*:*",
            "vulnerable": true
          }
        ],
        "negate": false,
        "operator": "OR"
      }
    ],
    "operator": "OR"
  }
]
```

## Severity and prioritization

- CVSS 3.1: 7.7 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N; source: CNA: redhat

- CVSS 3.1: 7.7 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N; source: ADP: redhat-SADP

- CVSS 3.1: 6.5 (medium); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N; source: NVD: nvd@nist.gov

- CVSS 3.1: 7.7 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N; source: NVD: secalert@redhat.com

- CVSS 3.1: 7.7 (high); CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N; source: NVD: 0b0ca135-0b70-47e7-9f44-1890c2a1c46c

- CISA KEV: No listing in collected sources

- EPSS: 0.40% as of 2026-11-04; percentile 33.93%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-918

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://access.redhat.com/errata/RHSA-2026:54583 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:54602 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:54770 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:57408 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:65852 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:70587 (CNA: redhat; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-42965 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2483184 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

- https://access.redhat.com/security/cve/CVE-2026-42965 (ADP: redhat-SADP; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2483184 (ADP: redhat-SADP; issue-tracking, x_refsource_REDHAT)

- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42965.json (ADP: redhat-SADP; x_sadp-csaf-vex)

- https://access.redhat.com/errata/RHSA-2026:57408 (ADP: redhat-SADP; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:54583 (ADP: redhat-SADP; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:54602 (ADP: redhat-SADP; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:54770 (ADP: redhat-SADP; vendor-advisory, x_refsource_REDHAT)

- https://access.redhat.com/errata/RHSA-2026:54583 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:54602 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:54770 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:57408 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:65852 (secalert@redhat.com)

- https://access.redhat.com/errata/RHSA-2026:70587 (secalert@redhat.com)

- https://access.redhat.com/security/cve/CVE-2026-42965 (secalert@redhat.com; Vendor Advisory)

- https://bugzilla.redhat.com/show_bug.cgi?id=2483184 (secalert@redhat.com; Issue Tracking, Vendor Advisory)

- https://access.redhat.com/errata/RHSA-2026:54583 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)

- https://access.redhat.com/errata/RHSA-2026:54602 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)

- https://access.redhat.com/errata/RHSA-2026:54770 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)

- https://access.redhat.com/errata/RHSA-2026:57408 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)

- https://access.redhat.com/security/cve/CVE-2026-42965 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c; Vendor Advisory)

- https://bugzilla.redhat.com/show_bug.cgi?id=2483184 (0b0ca135-0b70-47e7-9f44-1890c2a1c46c; Issue Tracking, Vendor Advisory)

- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-42965.json (0b0ca135-0b70-47e7-9f44-1890c2a1c46c)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-42965; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-42965; retrieved 2026-11-04; source updated 2026-11-04

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-42965; retrieved 2026-11-04; source updated Not reported

Revision: 5cfcf84e0faea394caf9b2db4a2c1082f413b5c433adba8b6c0a2b4d3ca3aaa2

Canonical: https://y2.dev/cve/CVE-2026-42965

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