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TI-2026-51400 Aliases CVE-2026-73266GHSA-xp42-v53j-r9gh

Clusterclaims-controller: confused deputy: tenant-controlled clusterclaim labels…

Priority LOW 31CWE-441Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
—
Confidentiality · integrity · availability
High · Low · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

A flaw was found in the clusterclaims-controller component of Multicluster Engine (MCE). An authenticated tenant can exploit this vulnerability by manipulating ClusterClaim labels. This allows the tenant to force a cluster to join a ManagedClusterSet belonging to another tenant. Such unauthorized access could enable the injection of policies and workloads into other tenants' clusters.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00352 29th percentileScored 2026-11-07
Fix Fixed Red Hat: 6 advisories

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
Red Hatmulticluster engine for Kubernetes 2.10—1787196014Patch availableCNA
Red Hatmulticluster engine for Kubernetes 2.11—1787239442Patch availableCNA
Red Hatmulticluster engine for Kubernetes 2.17—1786577950Patch availableCNA
Red Hatmulticluster engine for Kubernetes 2.6—1787259112Patch availableCNA
Red Hatmulticluster engine for Kubernetes 2.8—1787259059Patch availableCNA
Red Hatmulticluster engine for Kubernetes 2.9—1787195995Patch availableCNA
  • multicluster engine for Kubernetes 2.10 VendorRed Hat Affected — Fixed in 1787196014 Patch available CNA
  • multicluster engine for Kubernetes 2.11 VendorRed Hat Affected — Fixed in 1787239442 Patch available CNA
  • multicluster engine for Kubernetes 2.17 VendorRed Hat Affected — Fixed in 1786577950 Patch available CNA
  • multicluster engine for Kubernetes 2.6 VendorRed Hat Affected — Fixed in 1787259112 Patch available CNA
  • multicluster engine for Kubernetes 2.8 VendorRed Hat Affected — Fixed in 1787259059 Patch available CNA
  • multicluster engine for Kubernetes 2.9 VendorRed Hat Affected — Fixed in 1787195995 Patch available CNA

CPE names CNA · 6

CPEVersionsRoleVendor
cpe:/a:redhat:multicluster_engine:2.10::el92.10—Red Hat
cpe:/a:redhat:multicluster_engine:2.11::el92.11—Red Hat
cpe:/a:redhat:multicluster_engine:2.17::el92.17—Red Hat
cpe:/a:redhat:multicluster_engine:2.6::el92.6—Red Hat
cpe:/a:redhat:multicluster_engine:2.8::el92.8—Red Hat
cpe:/a:redhat:multicluster_engine:2.9::el92.9—Red Hat
  • cpe:/a:redhat:multicluster_engine:2.10::el9 Versions 2.10 — ·Red Hat
  • cpe:/a:redhat:multicluster_engine:2.11::el9 Versions 2.11 — ·Red Hat
  • cpe:/a:redhat:multicluster_engine:2.17::el9 Versions 2.17 — ·Red Hat
  • cpe:/a:redhat:multicluster_engine:2.6::el9 Versions 2.6 — ·Red Hat
  • cpe:/a:redhat:multicluster_engine:2.8::el9 Versions 2.8 — ·Red Hat
  • cpe:/a:redhat:multicluster_engine:2.9::el9 Versions 2.9 — ·Red Hat

Remediation

Red Hat 6 advisories

  • RHSA-2026:59593 Released 2026-08-25 · Red Hat rating Important
    multicluster engine for Kubernetes v2.17.2 security update
    • multicluster engine for Kubernetes 2.17 registry.redhat.io/multicluster-engine/cluster-api-provider-kubevirt-rhel9, registry.redhat.io/multicluster-engine/cluster-curator-controller-rhel9, registry.redhat.io/multicluster-engine/cluster-image-set-controller-rhel9 +6
  • RHSA-2026:59579 Released 2026-08-25 · Red Hat rating Important
    multicluster engine for Kubernetes v2.6.14 security update
    • multicluster engine for Kubernetes 2.6 registry.redhat.io/multicluster-engine/addon-manager-rhel9, registry.redhat.io/multicluster-engine/cluster-curator-controller-rhel9, registry.redhat.io/multicluster-engine/cluster-image-set-controller-rhel9 +17
  • RHSA-2026:59559 Released 2026-08-25 · Red Hat rating Important
    multicluster engine for Kubernetes v2.9.7 security update
    • multicluster engine for Kubernetes 2.9 registry.redhat.io/multicluster-engine/addon-manager-rhel9, registry.redhat.io/multicluster-engine/cluster-curator-controller-rhel9, registry.redhat.io/multicluster-engine/cluster-image-set-controller-rhel9 +15
Show 3 more Red Hat advisories
  • RHSA-2026:59558 Released 2026-08-25 · Red Hat rating Important
    multicluster engine for Kubernetes v2.8.10 security update
    • multicluster engine for Kubernetes 2.8 registry.redhat.io/multicluster-engine/addon-manager-rhel9, registry.redhat.io/multicluster-engine/backplane-rhel9-operator, registry.redhat.io/multicluster-engine/cluster-api-provider-agent-rhel9 +20
  • RHSA-2026:59557 Released 2026-08-25 · Red Hat rating Important
    multicluster engine for Kubernetes v2.10.6 security update
    • multicluster engine for Kubernetes 2.10 registry.redhat.io/multicluster-engine/addon-manager-rhel9, registry.redhat.io/multicluster-engine/cluster-curator-controller-rhel9, registry.redhat.io/multicluster-engine/cluster-image-set-controller-rhel9 +16
  • RHSA-2026:59556 Released 2026-08-25 · Red Hat rating Important
    multicluster engine for Kubernetes v2.11.6 security update
    • multicluster engine for Kubernetes 2.11 registry.redhat.io/multicluster-engine/addon-manager-rhel9, registry.redhat.io/multicluster-engine/cluster-curator-controller-rhel9, registry.redhat.io/multicluster-engine/cluster-image-set-controller-rhel9 +14

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
multicluster engine for Kubernetes 2.10Fixed RHSA-2026:59557
multicluster engine for Kubernetes 2.11Fixed RHSA-2026:59556
multicluster engine for Kubernetes 2.17Fixed RHSA-2026:59593
multicluster engine for Kubernetes 2.6Fixed RHSA-2026:59579
multicluster engine for Kubernetes 2.8Fixed RHSA-2026:59558
multicluster engine for Kubernetes 2.9Fixed RHSA-2026:59559
Not affected: 6 products
  • multicluster engine for Kubernetes 2.10
  • multicluster engine for Kubernetes 2.11
  • multicluster engine for Kubernetes 2.17
  • multicluster engine for Kubernetes 2.6
  • multicluster engine for Kubernetes 2.8
  • multicluster engine for Kubernetes 2.9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-73266
  2. 2026-10-03 Alias added: GHSA-xp42-v53j-r9gh

References

  • TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
  • TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
See all 7413 →

Sources