CVE-2026-66785
Submariner: submariner: missing validation of remote endpoint subnets and clusterid enables cross-cluster traffic hijack
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
8.7
Submariner: submariner: missing validation of remote endpoint subnets and clusterid enables cross-cluster traffic hijack
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.
- Record
CVE-2026-66785- CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-345
- Updated
- 2026-11-02
EUVDEUVD-2026-63572
8.7
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.
- Record
EUVD-2026-63572- CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-37mq-728j-5q43
9.9
A flaw was found in Submariner. This vulnerability allows a malicious cluster (spoke) to redirect...
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.
- Record
GHSA-37mq-728j-5q43- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - Weakness
- CWE-20, CWE-345, CWE-732
- Updated
- 2026-11-02
NVD
8.7
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.
- Record
CVE-2026-66785- CVSS 3.1
- 8.7 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N - Weakness
- CWE-345
- Updated
- 2026-11-02
Affected products
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-66785 is a high vulnerability (CVSS 8.7) in Red Hat Advanced Cluster Management For Kubernetes 2, published August 20, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.21%, the 10th percentile. No source names a fixed version.