GPUStack: Missing authorization in cluster API proxy (CVE-2026-103002)

GPUStack versions 2.2.0 through 2.2.1 contain a missing authorization vulnerability in the cluster_apiserver_proxy handler. This flaw allows an authenticated non-administrative user to bypass resource-level authorization checks when forwarding requests to a Kubernetes cluster. The vulnerability stems from the proxy handler failing to validate user permissions before forwarding traffic through a worker node using its associated Kubernetes ServiceAccount.

Impact

An attacker can leverage the ServiceAccount permissions of the worker node to interact with the Kubernetes cluster API. Depending on the privileges assigned to that ServiceAccount, observed and potential impacts include unauthorized reading of Kubernetes resources, modification of existing workloads, disruption of services through resource deletion, and potential remote code execution by creating attacker-controlled workloads.

Recommendation

• Upgrade gpustack to version v2.2.2 or later immediately to patch CVE-2026-103002.
• Until the upgrade is deployed, restrict access to the GPUStack web interface and API to trusted administrative accounts only.
• Review Kubernetes RBAC roles and cluster role bindings associated with GPUStack worker ServiceAccounts to ensure they follow the principle of least privilege.