CVE-2026-71471: ACM Search V2 RCE Vulnerability

CVE-2026-71471 Overview

A flaw exists in the acm-search-v2-rhel9 component of Red Hat Advanced Cluster Management (ACM). The vulnerability resides in the Collector.ImageOverride field of the Search Custom Resource (CR). An attacker with administrative privileges and patch access to the Search CR on the hub cluster can specify an arbitrary container image. That image is then deployed across all managed clusters in the fleet. The result is remote code execution (RCE) on every managed cluster, enabling command execution and access to sensitive data throughout the environment. This weakness is classified under CWE-829: Inclusion of Functionality from Untrusted Control Sphere.

Critical Impact
An authenticated hub-cluster administrator can deploy an attacker-controlled container image to every managed cluster, achieving fleet-wide remote code execution.

Affected Products

Red Hat Advanced Cluster Management acm-search-v2-rhel9 component
Hub clusters exposing the Search Custom Resource
Managed clusters receiving Search collector deployments

Discovery Timeline

2026-08-12 - CVE CVE-2026-71471 published to NVD
2026-08-12 - Last updated in NVD database

Technical Details for CVE-2026-71471

Vulnerability Analysis

The Search component in Red Hat Advanced Cluster Management deploys collector pods on managed clusters to gather resource metadata. The Collector.ImageOverride field in the Search CR lets operators substitute the collector image. The field accepts any container reference without restricting it to trusted registries or signed images. An administrator with patch permission on the Search CR can point the collector at a malicious image. The hub then propagates that image reference to every managed cluster, where the malicious container runs with the collector's service account privileges. This provides a single-point pivot from the hub into all connected clusters.

Root Cause

The vulnerability stems from missing validation and allow-listing on the Collector.ImageOverride field. The Search operator treats the override as trusted input and forwards it to workload manifests without policy checks. This aligns with CWE-829, where functionality is included from an untrusted control sphere. Least-privilege boundaries between hub-cluster admins and managed-cluster workloads are not enforced for this field.

Attack Vector

An attacker must first obtain administrative privileges on the hub cluster with patch access to the Search CR. The attacker submits a patch that sets Collector.ImageOverride to a container image they control. The Search operator reconciles the change and instructs each managed cluster to pull and run the specified image. The container executes attacker code on every managed cluster, providing command execution and access to secrets, tokens, and workloads on each. Exploitation requires no user interaction and traverses the trust boundary between the hub and managed clusters, resulting in a scope change.

No public proof-of-concept has been released. Refer to the Red Hat CVE-2026-71471 Advisory and Red Hat Bug Report #2512150 for vendor technical details.

Detection Methods for CVE-2026-71471

Indicators of Compromise

Search Custom Resources containing a Collector.ImageOverride value that references a registry outside the approved Red Hat container registries.
Collector pods on managed clusters running images with unexpected digests, tags, or repository paths.
Unusual outbound network connections from open-cluster-management-agent-addon namespaces to unknown hosts.
Kubernetes audit log entries showing patch operations against searches.search.open-cluster-management.io resources by non-routine identities.

Detection Strategies

Enable Kubernetes audit logging on the hub cluster and alert on any PATCH or UPDATE action targeting the Search CR, especially changes touching the Collector.ImageOverride field.
Use admission controllers such as OPA Gatekeeper or Kyverno to reject Search CR mutations that set Collector.ImageOverride to unapproved registries.
Compare running collector image digests across managed clusters against a known-good baseline and alert on drift.

Monitoring Recommendations

Forward hub and managed-cluster audit logs to a central SIEM for correlation of Search CR changes with subsequent pod events.
Monitor image pull events on managed clusters for references sourced from external or newly observed registries.
Track service-account token usage from collector pods to identify lateral movement following image substitution.

How to Mitigate CVE-2026-71471

Immediate Actions Required

Audit current Search CR definitions on every hub cluster and verify that Collector.ImageOverride is unset or points only to trusted Red Hat images.
Restrict patch and update RBAC verbs on searches.search.open-cluster-management.io to a minimal set of break-glass accounts.
Rotate credentials and service-account tokens on managed clusters if unauthorized image overrides are found.

Patch Information

Apply the fixes referenced in the Red Hat CVE-2026-71471 Advisory. Consult the advisory for the specific acm-search-v2-rhel9 package versions that resolve the flaw and follow Red Hat's ACM upgrade procedure for both hub and managed clusters.

Workarounds

Deploy an admission policy that denies any Search CR containing a non-empty Collector.ImageOverride value.
Remove patch permissions on the Search CR from all administrator role bindings that do not require them.
Enforce image signature verification on managed clusters so only signed, approved collector images can run.

bash

# Example Kyverno policy to block untrusted Collector.ImageOverride values
apiVersion: kyverno.io/v1
kind: ClusterPolicy
metadata:
  name: restrict-acm-search-image-override
spec:
  validationFailureAction: Enforce
  rules:
    - name: deny-untrusted-collector-image
      match:
        any:
          - resources:
              kinds:
                - search.open-cluster-management.io/v1alpha1/Search
      validate:
        message: "Collector.ImageOverride must reference registry.redhat.io"
        pattern:
          spec:
            collector:
              =(imageOverride): "registry.redhat.io/*"