CVE-2026-66787

Lighthouse: lighthouse: cross-cluster dns spoofing via unvalidated endpointslice ip addresses

Published Aug 20, 2026 CVSS 3.1 · 8.7 High EPSS < 1% KEV · Not listed
Description
A flaw was found in the lighthouse component of Red Hat Advanced Cluster Management for Kubernetes. This vulnerability stems from insufficient validation of advertised IP addresses within EndpointSlice objects. A compromised spoke cluster can exploit this by creating EndpointSlices with attacker-controlled IP addresses, causing other clusters' lighthouse DNS to redirect legitimate service traffic to malicious endpoints. This enables a remote attacker to conduct transparent Man-in-the-Middle (MITM) attacks on cross-cluster service communications, potentially leading to unauthorized information disclosure and data manipulation.

Remediation

Vendor Workaround

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Weaknesses CWE-489
Type Values Removed Values Added
Title Lighthouse: go pprof profiling endpoint enabled unconditionally on lighthouse-agent :8082 Lighthouse: lighthouse: cross-cluster dns spoofing via unvalidated endpointslice ip addresses
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L'}

cvssV3_1

{'score': 8.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N'}

Type Values Removed Values Added
CPEs cpe:/a:redhat:acm:2 cpe:/a:redhat:acm:2.17::el9
References
Type Values Removed Values Added
Title Lighthouse: lighthouse: cross-cluster dns spoofing via unvalidated endpointslice and serviceimport ips Lighthouse: go pprof profiling endpoint enabled unconditionally on lighthouse-agent :8082
Weaknesses CWE-489
Metrics cvssV3_1

{'score': 8.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N'}

cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L'}

Type Values Removed Values Added
First Time appeared Redhat advanced Cluster Management For Kubernetes
Vendors & Products Redhat advanced Cluster Management For Kubernetes
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in the lighthouse component of Red Hat Advanced Cluster Management for Kubernetes. This vulnerability stems from insufficient validation of advertised IP addresses within EndpointSlice objects. A compromised spoke cluster can exploit this by creating EndpointSlices with attacker-controlled IP addresses, causing other clusters' lighthouse DNS to redirect legitimate service traffic to malicious endpoints. This enables a remote attacker to conduct transparent Man-in-the-Middle (MITM) attacks on cross-cluster service communications, potentially leading to unauthorized information disclosure and data manipulation.
Title Lighthouse: lighthouse: cross-cluster dns spoofing via unvalidated endpointslice and serviceimport ips
First Time appeared Redhat
Redhat acm
Weaknesses CWE-345
CPEs cpe:/a:redhat:acm:2
Vendors & Products Redhat
Redhat acm
References
Metrics cvssV3_1

{'score': 8.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Oct 19, 2026, 5:02 PM
Reserved
Jul 27, 2026, 5:51 PM
Status
Awaiting Analysis
Published
Aug 20, 2026, 7:16 PM
Modified
Oct 19, 2026, 5:17 PM
Severity
Important
Public date
Aug 20, 2026, 5:20 PM