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Fencer Vulns
critical 9.0

CVE-2026-10090 json

Multicluster-operators-subscription: multicluster-operators-subscription: namespace edit user can deploy cluster-scoped clusterrolebinding and become cluster-admin via application subscription

published 2026-08-05 3 mo ago modified 2026-10-23 16 d ago also EUVD-2026-53294

cvss
9.0
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 47%
public exploits
0
none known

Summary

A flaw was found in the Application Subscription controller (multicluster-operators-subscription) of Red Hat Advanced Cluster Management for Kubernetes (ACM). A user with namespace-scoped "edit" privileges in an ACM hub namespace can create a Channel resource pointing to a Helm repository they control and a Subscription resource referencing it. The app-subscription controller fetches and applies the Helm chart contents with its own elevated authority, without verifying whether the subscription creator holds the "open-cluster-management:subscription-admin" role and without restricting applied resources to the subscription namespace. This allows the attacker to include cluster-scoped resources in the Helm chart, such as a ClusterRoleBinding granting the attacker's ServiceAccount the "cluster-admin" ClusterRole. Successful exploitation results in full cluster-admin privilege escalation. This contradicts the ACM documentation which states that non-subscription-admin users should have resources deployed into the subscription namespace only.

Patch / fix

  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.11 1787263584
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.13 1787263693
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.14 1787170830
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.15 1787240030
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.16 1787242321
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.17 1787242108

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-10090 updated cvss 9.0

multicluster-operators-subscription: multicluster-operators-subscription: namespace edit user can deploy cluster-scoped ClusterRoleBinding and become cluster-admin via Application Subscription

  • Red Hat Advanced Cluster Management for Kubernetes 2.11 rhacm2/multicluster-operators-subscription-rhel9 1787263584
    fixed: vendor fix RHSA-2026:60387
  • Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/multicluster-operators-subscription-rhel9 1787263693
    fixed: vendor fix RHSA-2026:60390
  • Red Hat Advanced Cluster Management for Kubernetes 2.14 rhacm2/multicluster-operators-subscription-rhel9 1787170830
    fixed: vendor fix RHSA-2026:60388
  • Red Hat Advanced Cluster Management for Kubernetes 2.15 rhacm2/multicluster-operators-subscription-rhel9 1787240030
    fixed: vendor fix RHSA-2026:60389
  • Red Hat Advanced Cluster Management for Kubernetes 2.16 rhacm2/multicluster-operators-subscription-rhel9 1787242321
    fixed: vendor fix RHSA-2026:60391
  • Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/multicluster-operators-subscription-rhel9 1787242108
    fixed: vendor fix RHSA-2026:60386
  • Red Hat Advanced Cluster Management for Kubernetes 2.11 rhacm2/thanos-rhel9 1787685239, rhacm2/console-rhel9 1787687062, rhacm2/prometheus-rhel9 1787261499, rhacm2/acm-grafana-rhel9 1787682482, rhacm2/acm-search-v2-rhel9 1787688827, rhacm2/node-exporter-rhel9 1787263326, +34 more Red Hat Advanced Cluster Management for Kubernetes 2.13 rhacm2/thanos-rhel9 1787263906, rhacm2/acm-cli-rhel9 1787259085, rhacm2/console-rhel9 1787339249, rhacm2/prometheus-rhel9 1787263757, rhacm2/acm-grafana-rhel9 1787644958, rhacm2/acm-search-v2-rhel9 1787682112, +37 more Red Hat Advanced Cluster Management for Kubernetes 2.14 rhacm2/thanos-rhel9 1787614805, rhacm2/acm-cli-rhel9 1786923505, rhacm2/console-rhel9 1787339248, rhacm2/prometheus-rhel9 1786976997, rhacm2/acm-grafana-rhel9 1787645355, rhacm2/acm-search-v2-rhel9 1787682033, +37 more Red Hat Advanced Cluster Management for Kubernetes 2.15 rhacm2/thanos-rhel9 1787238739, rhacm2/acm-cli-rhel9 1787238522, rhacm2/console-rhel9 1787341780, rhacm2/prometheus-rhel9 1787238666, rhacm2/acm-grafana-rhel9 1787645007, rhacm2/acm-search-v2-rhel9 1787681674, +39 more Red Hat Advanced Cluster Management for Kubernetes 2.16 rhacm2/thanos-rhel9 1786909435, rhacm2/acm-cli-rhel9 1786908319, rhacm2/console-rhel9 1787339213, rhacm2/prometheus-rhel9 1786909036, rhacm2/acm-grafana-rhel9 1787645431, rhacm2/acm-search-v2-rhel9 1787681686, +40 more Red Hat Advanced Cluster Management for Kubernetes 2.17 rhacm2/thanos-rhel9 1787229716, rhacm2/acm-cli-rhel9 1787227626, rhacm2/console-rhel9 1787335105, rhacm2/prometheus-rhel9 1787230287, rhacm2/acm-grafana-rhel9 1787316467, rhacm2/acm-search-v2-rhel9 1787681651, +39 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
3 mo ago

Exploit prediction

0.58% chance of exploitation in the next 30 days, higher than 47% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 9.0 CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L

Affected products

  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.11
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.13
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.14
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.15
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.16
  • Red Hat Red Hat Advanced Cluster Management for Kubernetes 2.17

Classification

Weakness
  • CWE-267 Privilege Defined With Unsafe Actions

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.