LiveActive security incident?Get immediate response
CVE Record

CVE-2026-10090: Multicluster-operators-subscription: multicluster-operators-subscription: namespace edit user can deploy cluster-scoped clusterrolebinding and become cluster-admin via application subscription

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.

CriticalCVSS 9Not KEV-listedUpdated
Discuss exposureBack to CVEs
Glexia's TakeAutomated analysiscritical

Security readout for executives and security teams

Plain-English summary

A user who can edit one ACM hub namespace may abuse the subscription controller’s broader permissions to become cluster administrator. Successful exploitation could expose sensitive cluster data, permit unauthorized changes, and disrupt workloads. The issue is critical because a limited namespace role can cross a major security boundary.

Executive priority

Treat as an urgent privileged-access issue on affected ACM hubs. Prioritize internet-reachable or broadly administered environments and hubs where many users hold namespace edit rights. Apply vendor guidance promptly, tighten subscription permissions, and investigate suspicious cluster-admin bindings. No active exploitation is established by the supplied evidence.

Technical view

The Application Subscription controller accepts attacker-controlled Helm content through Channel and Subscription resources, then applies it using elevated controller authority. It neither verifies the creator has the subscription-admin role nor confines resources to the subscription namespace. Cluster-scoped resources can therefore create a ClusterRoleBinding that elevates the attacker’s ServiceAccount to cluster-admin.

Likely exposure

Exposure applies to listed Red Hat ACM 2.11, 2.13, 2.14, 2.15, 2.16, and 2.17 package builds. Exploitation requires namespace-scoped edit privileges in an ACM hub namespace and the ability to create relevant Channel and Subscription resources referencing controlled Helm content.

Exploitation context

The supplied record describes network-accessible, low-complexity privilege escalation requiring substantial existing privileges but no user interaction. Successful exploitation changes scope and grants cluster-admin authority. KEV is false, and the supplied sources provide no evidence of active exploitation or a public exploit.

Researcher notes

The weakness is categorized as CWE-267 and scored CVSS 3.1 9.0: AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L. The supplied affected-version values appear to be package build identifiers. Exact fixed builds and advisory-specific remediation details are not included, so consult the matching RHSA rather than inferring version thresholds.

Mitigation direction

  • Identify affected ACM hubs and match installed package builds against the listed affected versions.
  • Review the applicable Red Hat security advisory and apply its vendor-provided update.
  • Until updated, restrict Channel and Subscription creation to trusted subscription administrators.
  • Review namespace edit grants on ACM hub namespaces and remove unnecessary access.
  • Restrict untrusted or unnecessary Helm repository sources where operationally feasible.

Validation and detection

  • Inventory ACM versions and the multicluster-operators-subscription-rhel9 package build on every hub.
  • Verify only intended administrators can create or modify Channel and Subscription resources.
  • Review audit records for unexpected Channels, Subscriptions, Helm sources, and related cluster-scoped resources.
  • Inspect recent ClusterRoleBindings for unexpected subjects or cluster-admin grants associated with application subscriptions.
  • After remediation, confirm installed builds match the applicable Red Hat advisory.
Prepared
Confidence
high
Sources
10

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · low confidence lookup

CWE-267: Exact CWE lookup

Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

Open ATT&CK lookup
description · low confidence lookup

Privilege behavior lookup

The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
description · low confidence lookup

Container behavior lookup

The affected technology mentions containers, so container-specific ATT&CK technique review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.

Open ATT&CK lookup
cve · low confidence lookup

CVE-2026-10090 mapping review

Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.

Open ATT&CK lookup
Vulnerability profileCVE Program record
Severity
Critical
CVSS
9 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
5Timeline events
1ADP providers
9Source links

SSVC decision data

CISA-ADPCISA Coordinator
Timestamp
Version
2.0.3
Exploitation: noneAutomatable: noTechnical Impact: total

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
9CVSS 3.1CriticalCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L2.36redhat

Vulnerability scoring details

Base CVSS 3.1 score

9Critical
CVSS 3.1 vector shape for CVE-2026-10090Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Vulnerability timeline

Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.

  1. Source timelineredhat

    Reported to Red Hat.

  2. CVE reservedCVE Program

    The CVE ID was reserved by the assigning CNA.

  3. Source timelineredhat

    Made public.

  4. CVE publishedCVE Program

    The CVE record was published.

  5. CVE updatedCVE Program

    The CVE record metadata indicates this as the latest update time.

ADP provider summaries

CISA-ADPCISA ADP Vulnrichment
other:ssvc

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.11rhacm2/multicluster-operators-subscription-rhel9, 1787263584affected
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.13rhacm2/multicluster-operators-subscription-rhel9, 1787263693affected
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.14rhacm2/multicluster-operators-subscription-rhel9, 1787170830affected
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.15rhacm2/multicluster-operators-subscription-rhel9, 1787240030affected
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.16rhacm2/multicluster-operators-subscription-rhel9, 1787242321affected
Red HatRed Hat Advanced Cluster Management for Kubernetes 2.17rhacm2/multicluster-operators-subscription-rhel9, 1787242108affected
Weakness

CWE details

CWE-267

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-267 · source CWE mapping

Privilege Defined With Unsafe Actions

Privilege Defined With Unsafe Actions represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

Open CWE intelligenceSame-CWE CVEs