Red Hat Advanced Cluster Management for Kubernetes lighthouse input validation

Summaryinfo

A vulnerability marked as problematic has been reported in Red Hat Advanced Cluster Management for Kubernetes. The affected element is an unknown function of the component lighthouse. This manipulation causes input validation. This vulnerability is tracked as CVE-2026-66787. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in Red Hat Advanced Cluster Management for Kubernetes (the affected version is unknown) and classified as problematic. Affected by this vulnerability is an unknown code of the component lighthouse. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at access.redhat.com. This vulnerability is known as CVE-2026-66787 since 07/27/2026. The exploitation appears to be easy. The attack can be launched remotely. Additional levels of successful authentication are required for exploitation. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $5k-$25k at the moment (estimation calculated on 08/20/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• Virtualization Software

Vendor

• Red Hat

Name

• Advanced Cluster Management for Kubernetes

License

• open-source

Website

• Vendor: https://www.redhat.com/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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