CyberSecBulletin
CVE-2026-73267NVD status: Awaiting Analysis

multicluster engine for Kubernetes 2.10: Client-Side Enforcement of Server-Side Security

Published Updated By the CyberSecBulletin desk

CVE-2026-73267 is a high-severity client-side enforcement of server-side security vulnerability in multicluster engine for Kubernetes 2.10 from Red Hat, with a CVSS 3.1 base score of 7.7 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.63% chance of exploitation within 30 days, higher than 51% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of multicluster engine for Kubernetes 2.10 you run against the affected versions below, and install the vendor's latest release.

Affected products and versions

VendorProductAffected versionsFixed in
Red Hatmulticluster engine for Kubernetes 2.10Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.11Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.17Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.6Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.8Not specified in the recordNot stated
Red Hatmulticluster engine for Kubernetes 2.9Not specified in the recordNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H. Scored by CNA (redhat.com).

Official description

A flaw was found in the clusterclaims-controller component of multicluster engine (MCE). A tenant with standard permissions to create and delete ClusterClaim resources can exploit this by manipulating the `spec.namespace` field. This allows the tenant to specify and delete any ManagedCluster, including the hub's local-cluster or other tenants' clusters, due to a missing ownership check. This vulnerability can lead to a denial of service by enabling unauthorized deletion of ManagedClusters.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Client-Side Enforcement of Server-Side Security

The product includes a server that relies on the client to implement a protection mechanism that is intended to protect the server.

How developers prevent this class of flaw

  • If some degree of trust is required between the two entities, then use integrity checking and strong authentication to ensure that the inputs are coming from a trusted source. Design the product so that this trust is managed in a centralized fashion, especially if there are complex or numerous communication channels, in order to reduce the risks that the implementer will mistakenly omit a check in a single code path.

More Client-Side Enforcement of Server-Side Security vulnerabilities (CWE-602)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in multicluster engine for Kubernetes 2.10

All multicluster engine for Kubernetes 2.10 vulnerabilities

Recent Client-Side Enforcement of Server-Side Security vulnerabilities

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