CVE-2026-66785

Submariner: submariner: missing validation of remote endpoint subnets and clusterid enables cross-cluster traffic hijack

State: Published
Severity: 8.7 High
Published: Aug 20, 2026
Updated: Oct 19, 2026
Reserved: Jul 27, 2026

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Description

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.

Scores

CVSS	Score	Vector	Source
3.1	8.7 High	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N	redhat

Weaknesses

CWE-345 Insufficient Verification of Data Authenticity

Affected Products

Product	Versions
Red Hat Advanced Cluster Management for Kubernetes 2.16Red Hat	1790670439 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.16Red Hat	1790670231 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.16Red Hat	1790670243 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.16Red Hat	1790670508 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.16Red Hat	1790670233 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.16Red Hat	1790670912 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.16Red Hat	1790670254 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.17Red Hat	1788023916 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.17Red Hat	1788023940 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.17Red Hat	1788105072 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.17Red Hat	1788043964 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.17Red Hat	1788043961 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.17Red Hat	1788073481 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2.17Red Hat	1788043970 and laterNot affected
Red Hat Advanced Cluster Management for Kubernetes 2Red Hat
Red Hat Advanced Cluster Management for Kubernetes 2Red Hat

References

RHSA-2026:63016vendor-advisory
RHSA-2026:85227vendor-advisory
https://access.redhat.com/security/cve/CVE-2026-66785vdb-entry
RHBZ#2507530issue-tracking

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