---
id: CVE-2026-66785
title: A flaw was found in Submariner
summary: >-
  A flaw was found in Submariner. This vulnerability allows a malicious cluster
  (spoke) to redirect network traffic from other connected clusters (peer
  clusters) by publishing a specially crafted network endpoint. The system fails
  to prope…
severity: high
cvss: 8.7
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N'
cwe:
  - CWE-345
published: '2026-08-20'
updated: '2026-10-13'
sourceUpdated: '2026-10-13T18:17:25.717'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-66785'
references:
  - url: 'https://access.redhat.com/errata/RHSA-2026:63016'
    label: secalert@redhat.com
  - url: 'https://access.redhat.com/security/cve/CVE-2026-66785'
    label: secalert@redhat.com
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2507530'
    label: secalert@redhat.com
tags:
  - nvd
epss: 0.00126
epssPercentile: 0.02051
ingestedAt: '2026-10-13T18:41:42.721Z'
---

## Overview

A flaw was found in Submariner. This vulnerability allows a malicious cluster (spoke) to redirect network traffic from other connected clusters (peer clusters) by publishing a specially crafted network endpoint. The system fails to properly validate the network subnets provided by the malicious cluster, enabling it to declare arbitrary network ranges. Consequently, all network traffic intended for these arbitrary ranges from peer clusters will be rerouted through the attacker's tunnel, potentially leading to unauthorized information disclosure or network disruption.

## Remediation

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