CVE-2026-10090 (CVSS 9.9)

Description

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.

Is your site exposed to CVE-2026-10090?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

9.9

CRITICAL

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

EPSS — Exploit Prediction

0.0037

Probability of exploitation

0.29%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-267 CWE-267

References

Other References

https://access.redhat.com/security/cve/CVE-2026-10090 https://bugzilla.redhat.com/show_bug.cgi?id=2483292

Frequently Asked Questions

What is CVE-2026-10090? +

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. It has a CVSS v3.1 base score of 9.9 (CRITICAL).

How severe is CVE-2026-10090? +

CVE-2026-10090 has a CVSS v3.1 score of 9.9 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0037, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-10090? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2025-2903

An attacker with knowledge of creating user accounts during VM deployment on Google Cloud Platform (GCP) using the OS Login …

CVE-2026-114524

Privilege Defined With Unsafe Actions vulnerability in Drupal Custom Formatters allows Privilege Escalation. This issue affects Custom Formatters versions: from …

CVE-2026-96363

Privilege Defined With Unsafe Actions vulnerability in Drupal Webform allows Stored XSS. This issue affects Webform versions: from 0.0.0 to …

CVE-2026-29646 9.8

In OpenXiangShan NEMU prior to 55295c4, when running with RVH (Hypervisor extension) enabled, a VS-mode guest write to the supervisor …

CVE-2026-96659 9.1

A flaw was found in Foreman. This vulnerability allows an authenticated user with low-level Viewer permissions to cause unauthorized information …

CVE-2024-55968 8.8

An issue was discovered in DTEX DEC-M (DTEX Forwarder) 6.1.1. The com.dtexsystems.helper service, responsible for handling privileged operations within the …