CVE-2026-66787 Lighthouse: lighthouse: cross-cluster dns spoofing via unvalidated endpointslice ip addresses
A compromised spoke cluster can spoof DNS entries to redirect cross-cluster traffic, enabling Man-in-the-Middle attacks and data manipulation.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-66787?
CVE-2026-66787 is a high-severity vulnerability in Red Hat Advanced Cluster Management for Kubernetes 2.16, published on 20 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official 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.
Weakness: CWE-345
Which versions are affected by CVE-2026-66787?
How do I fix CVE-2026-66787?
No fix has been published for CVE-2026-66787 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-66787 being exploited?
There is no known exploitation of CVE-2026-66787 in the wild and no public exploit code.
Sources
Also known as GHSA-7fh9-j94v-w42j.