CVE-2026-10090
CRITICAL 9A 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.
Severe if exploited (CVSS 9), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.4%chance of exploitation in 30 days · 29th percentile
Impact if exploited
9CVSS 3.1 · CRITICAL
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityLow
What an attacker needs
- ✓Access: Reachable over the network — no local access needed
- ⚠Privileges: Requires an admin / high-privilege account
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-10090/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-10090/poc.json
Affected
Vendors Red Hat
Products Red Hat Advanced Cluster Management For Kubernetes 2.11 Red Hat Advanced Cluster Management For Kubernetes 2.13 Red Hat Advanced Cluster Management For Kubernetes 2.14 Red Hat Advanced Cluster Management For Kubernetes 2.15 Red Hat Advanced Cluster Management For Kubernetes 2.16 Red Hat Advanced Cluster Management For Kubernetes 2.17
Weakness (CWE)
- CWE-267: Privilege Defined With Unsafe Actions
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L
All CVSS metrics
- CRITICAL 9 v3.1 · CNA Primary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L - CRITICAL 9 v3.1 · NVD Secondary
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:L