What is the CVSS score of CVE-2026-10090?

CVE-2026-10090 has a CVSS 3.1 base score of 9.0 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L. EPSS exploitation probability: 0.2%.

Which versions of Red Hat ACM are affected by CVE-2026-10090?

Red Hat Advanced Cluster Management for Kubernetes (ACM) contains a critical privilege escalation flaw that allows users with only namespace-scoped edit permissions to achieve cluster-admin control…

How to fix or mitigate CVE-2026-10090?

Within 24 hours: audit and immediately restrict who holds namespace-scoped 'edit' rights in ACM hub namespaces, enable detailed audit logging for Channel and Subscription object creation and application. Within 7 days: conduct full RBAC review across ACM hub and managed clusters, implement network policies to restrict hub cluster outbound connectivity to trusted Helm repositories only, and consider temporary disabling of app-subscription-controller if non-essential. Within 30 days: review Red Hat security advisories for patch availability and interim guidance, apply patch immediately upon release, and conduct forensics to identify any past unauthorized Channel or Subscription deployments.

Red Hat ACM CVE-2026-10090

EUVD-2026-53294 CRITICAL

Privilege Defined With Unsafe Actions (CWE-267)

2026-08-05 secalert@redhat.com

GHSA-g9vp-wj77-5767

Privilege Escalation Kubernetes Red Hat

9.0

CVSS 3.1 · Vendor: redhat

Severity by source

Vendor (redhat) PRIMARY

9.0 CRITICAL

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

vuln.today AI

9.9 CRITICAL

Reachable via the Kubernetes API (AV:N) with low complexity; requires only namespace 'edit' rights per the description so PR:L not PR:H; escalation beyond the namespace to cluster-admin gives S:C and full C/I/A:H.

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

4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

Red Hat

9.9 HIGH

qualitative

Primary rating from Vendor (redhat).

CVSS VectorVendor: redhat

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

Low

Lifecycle Timeline

Analysis Updated

Aug 12, 2026 - 22:28 vuln.today

v3 (cvss_changed)

CVSS changed

Aug 12, 2026 - 22:22 NVD

9.1 (CRITICAL) 9.0 (CRITICAL)

Analysis Updated

Aug 12, 2026 - 16:38 vuln.today

v2 (cvss_changed)

Re-analysis Queued

Aug 12, 2026 - 16:22 vuln.today

cvss_changed

CVSS changed

Aug 12, 2026 - 16:22 NVD

9.9 (CRITICAL) 9.1 (CRITICAL)

Analysis Generated

Aug 05, 2026 - 09:31 vuln.today

CVE Published

Aug 05, 2026 - 09:18 nvd

CRITICAL 9.9

DescriptionCVE.org

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.

Articles & Coverage 1

News Critical Privilege Escalation in Red Hat ACM for Kubernetes - CVE-2026-10090 Aug 05, 2026

AnalysisAI

Privilege escalation to cluster-admin in Red Hat Advanced Cluster Management for Kubernetes (ACM) lets a user holding only namespace-scoped 'edit' rights on an ACM hub namespace take over the entire cluster. By creating a Channel pointing to an attacker-controlled Helm repository and a Subscription referencing it, the app-subscription controller (multicluster-operators-subscription) applies the chart with its own elevated authority and without enforcing the subscription-admin role or namespace confinement, letting the chart install cluster-scoped objects such as a ClusterRoleBinding to cluster-admin. No public exploit identified at time of analysis, and EPSS is low (0.25%), but the technical impact is total and the flaw directly contradicts ACM's documented namespace-confinement guarantee.

Technical ContextAI

The affected component is the Application Subscription controller (multicluster-operators-subscription), part of ACM's GitOps/app-delivery model where a Channel defines a content source (here a Helm repository) and a Subscription pulls and reconciles that content onto managed targets. The controller runs with a high-privilege service account so it can deploy application resources, and ACM's design intends non-subscription-admin users to have content confined to the subscription's own namespace, with only holders of the 'open-cluster-management:subscription-admin' role permitted to deploy cluster-scoped or cross-namespace resources. The root cause maps to CWE-267 (Privilege Defined With Unsafe Actions): the controller performs a privileged action (applying arbitrary Helm chart manifests with cluster-wide authority) on behalf of a caller without checking whether that caller actually holds the subscription-admin role and without restricting the applied objects to the subscription namespace, so a low-privilege caller's request is executed with the controller's elevated identity. No CPE strings were supplied in the input, so exact affected build coordinates are not enumerable from this data.

Affected ProductsAI

The affected product is Red Hat Advanced Cluster Management for Kubernetes (ACM), specifically its Application Subscription controller shipped as the multicluster-operators-subscription component. The provided intelligence does not include CPE strings or a definitive fixed-version list, so exact affected version ranges cannot be enumerated from this data; consult the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-10090 and the tracking bug at https://bugzilla.redhat.com/show_bug.cgi?id=2483292 for authoritative version and errata details. The issue is also tracked as ENISA EUVD-2026-53294 (https://nvd.nist.gov/vuln/detail/CVE-2026-10090).

RemediationAI

Apply the Red Hat ACM erratum for CVE-2026-10090 once available; the input data does not contain an exact fixed version, so the specific patched release must be confirmed from the Red Hat advisory at https://access.redhat.com/security/cve/CVE-2026-10090 and Bugzilla 2483292 (https://bugzilla.redhat.com/show_bug.cgi?id=2483292) rather than assumed here. As compensating controls until patched: tighten RBAC so that namespace-scoped 'edit' on ACM hub namespaces is granted sparingly and audited, since that role is the exploitation prerequisite; restrict or deny the ability to create Channel and Subscription resources for non-trusted users via RBAC or an admission policy (e.g. OPA/Gatekeeper or Kyverno) that blocks Subscriptions from non-subscription-admin users and rejects charts containing cluster-scoped objects such as ClusterRoleBinding/ClusterRole from non-admin subscriptions - noting this may break legitimate self-service app deployment workflows; and constrain outbound access so the controller can only reach approved, internal Helm repositories, which prevents pointing Channels at attacker-controlled external repos but may disrupt teams relying on public charts. Monitor for anomalous ClusterRoleBinding creations tied to subscription service accounts as a detection backstop.