CyberSecBulletin
CVE-2026-66788NVD status: Awaiting Analysis

Red Hat Advanced Cluster Management for…: Use of Unmaintained Third Party Components

CVE-2026-66788 is a critical-severity use of unmaintained third party components vulnerability in Red Hat Advanced Cluster Management for Kubernetes 2.16 from Red Hat, with a CVSS 3.1 base score of 9.9 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.66% chance of exploitation within 30 days, higher than 52% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Red Hat Advanced Cluster Management for Kubernetes 2.16 you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.16Not specified in the recordNot stated
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.17Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
LowSome restricted data can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H. Scored by CNA (redhat.com).

Official description

A flaw was found in Lighthouse. A remote attacker, by compromising a spoke cluster, can exploit a vulnerability where the destination namespace for resource injection is derived from an attacker-controlled label or annotation on the broker object. This allows the attacker to inject unauthorized EndpointSlices and ServiceImports into any namespace on peer clusters, including critical system namespaces like kube-system and openshift-*. This could lead to privilege escalation or other forms of system compromise within the cluster.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Use of Unmaintained Third Party Components

The product relies on third-party components that are not actively supported or maintained by the original developer or a trusted proxy for the original developer.

More Use of Unmaintained Third Party Components vulnerabilities (CWE-1104)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Red Hat Advanced Cluster Management for Kubernetes 2.16

All Red Hat Advanced Cluster Management for Kubernetes 2.16 vulnerabilities

Recent Use of Unmaintained Third Party Components vulnerabilities

Spotted an error? Tell us.