Insufficient Validation Flaw in Red Hat Advanced Cluster Management for Kubernetes
CVE-2026-66787

5.4MEDIUM

Key Information:

Vendor

Red Hat
Status
Red Hat Advanced Cluster Management For Kubernetes 2.17
Vendor
CVE Published:
20 August 2026

What is CVE-2026-66787?

A flaw exists within the lighthouse component of Red Hat Advanced Cluster Management for Kubernetes that fails to properly validate advertised IP addresses in EndpointSlice objects. An attacker can exploit compromised spoke clusters by creating EndpointSlices with maliciously controlled IP addresses. This can result in the redirection of legitimate DNS traffic to harmful endpoints, facilitating Man-in-the-Middle (MITM) attacks during cross-cluster service communications. As a consequence, this vulnerability poses risks of unauthorized information disclosure and potential data manipulation.

Affected Version(s)

Red Hat Advanced Cluster Management for Kubernetes 2.17 1788023916

Red Hat Advanced Cluster Management for Kubernetes 2.17 1788023940

Red Hat Advanced Cluster Management for Kubernetes 2.17 1788105072

References

https://access.redhat.com/errata/RHSA-2026:63016
vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-66787
vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2507532
issue-trackingx_refsource_REDHAT

CVSS V3.1

Score:
5.4
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
None
Availability:
Low
Attack Vector:
Adjacent Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.