CVE-2026-18381 Red Hat CVE debrief

Who should care

Defenders responsible for OpenShift environments using the Cost Management Metrics Operator should assess exposure and prioritize remediation. This includes reviewing the current configuration of the CostManagementMetricsConfig custom resource and restricting access to it to prevent potential token leaks and unauthorized access. Additionally, defenders should verify exposure in OpenShift environments using the Cost Management Metrics Operator and monitor

Why it matters

CVE-2026-18381 is a high-severity vulnerability in the koku-metrics-operator for Red Hat OpenShift. Defenders should prioritize verifying exposure and restricting access to the affected custom resource to prevent potential token leaks and unauthorized access.

• Potential unauthorized access to Kubernetes service-account bearer tokens
• Possible lateral movement within OpenShift environments
• Need for verification of exposure in OpenShift environments
• Priority for restricting access to the CostManagementMetricsConfig custom resource

Technical summary

The koku-metrics-operator for Red Hat OpenShift has a flaw in its CostManagementMetricsConfig custom resource. Users able to edit this resource can specify an arbitrary upload URL. The operator attaches its Kubernetes service-account bearer token to queries sent to this user-controlled URL, potentially allowing attackers to obtain the token. This issue arises from the operator's handling of the custom resource, which allows a user to specify an arbitrary upload URL. The operator then attaches its own Kubernetes service-account bearer token to queries sent to this user-controlled URL.

Defensive priority

Defenders should prioritize verifying exposure in OpenShift environments using the Cost Management Metrics Operator and restrict access to the CostManagementMetricsConfig custom resource.

Recommended defensive actions

• Verify exposure in OpenShift environments using the Cost Management Metrics Operator
• Restrict access to the CostManagementMetricsConfig custom resource
• Monitor for suspicious activity related to the operator's service-account bearer token
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability in the koku-metrics-operator for Red Hat OpenShift. The flaw allows users with edit access to the CostManagementMetricsConfig custom resource to specify an arbitrary upload URL, potentially leading to unauthorized access to the Kubernetes service-account bearer token.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.