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CVE-2026-10090

CRITICAL 9

Published 2026-08-05 · Last modified 2026-08-12

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.

ELEVATED IMPACT

Severe if exploited (CVSS 9), but no known exploitation and low modeled probability. Patch on a normal cadence.

Exploitation likelihood

0.2%chance of exploitation in 30 days · 16th percentile

○ In CISA KEV ○ Public exploit / PoC

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

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

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

References

Technical & other

Sources: NVD · CVE.org · EPSS