CVE-2026-53487: 
vulnerability analysis and mitigation

CVE-2026-53487 is an authenticated cluster RBAC bypass vulnerability in Kite, a Kubernetes management dashboard, affecting all versions up to and including v0.12.2. Any authenticated Kite user with at least one role can query the /api/v1/overview endpoint for clusters they are not authorized to access by supplying an arbitrary cluster name via the x-cluster-name header. The vulnerability was discovered and reported by researcher DavidCarliez, first published May 31, 2026, and added to the GitHub Advisory Database on July 7, 2026. It carries a CVSS v3.1 base score of 4.3 (Medium) (GitHub Advisory, Kite Advisory).

The root cause is a missing authorization check (CWE-862) caused by a route registration ordering error in routes.go. The /api/v1/overview route is registered at line 135 before the global middleware.RBACMiddleware() is applied at line 171, meaning the RBAC middleware never executes for this endpoint. The ClusterMiddleware in pkg/middleware/cluster.go accepts the target cluster name from the x-cluster-name header, query parameter, or cookie and injects the corresponding ClientSet without verifying whether the requesting user has permission to access that cluster. The GetOverview handler in pkg/system/handler.go only checks len(user.Roles) > 0 — rejecting users with zero roles — but does not call rbac.CanAccessCluster(user, cs.Name), which is the check correctly used by other endpoints such as /api/v1/clusters (GitHub Advisory, Kite Advisory).

The impact is limited to confidentiality. A low-privileged authenticated user can retrieve aggregate Kubernetes inventory and resource sizing data — including total node count, pod count, namespace count, service count, and CPU/memory allocations — from any cluster configured in the Kite instance, regardless of their assigned cluster permissions. The advisory explicitly confirms that Kubernetes mutation, individual pod names, secret values, kubeconfig contents, and bearer tokens are not exposed through this endpoint, limiting the risk to information disclosure of cluster capacity metadata (GitHub Advisory).

1. Authenticate: Obtain valid Kite credentials for any account that has at least one role assigned, regardless of which cluster(s) that role permits access to.
2. Identify target cluster: Enumerate or guess the name of another cluster configured in the Kite instance (cluster names may be discoverable through UI elements or other API responses visible to the user).
3. Craft the request: Send a GET /api/v1/overview HTTP request to the Kite API, including the standard authentication token/session cookie and the x-cluster-name: <target-cluster> header set to the unauthorized cluster name.
4. Receive unauthorized data: The server bypasses RBAC checks and returns a JSON response containing aggregate inventory data for the target cluster, including totalNodes, totalPods, totalNamespaces, totalServices, and CPU/memory resource values.

Example request:

GET /api/v1/overview HTTP/1.1
Host: <kite-instance>
Authorization: Bearer <token>
x-cluster-name: prod-cluster

Example unauthorized response:

{"totalNodes":1,"readyNodes":0,"totalPods":1,"runningPods":0,"totalNamespaces":1,"totalServices":1,"prometheusEnabled":false,"resource":{"cpu":{"allocatable":0,"requested":0,"limited":0},"memory":{"allocatable":0,"requested":0,"limited":0}}}

(GitHub Advisory, Kite Advisory)

• Network: Repeated or anomalous GET /api/v1/overview requests from a single authenticated user session, particularly with varying x-cluster-name header values that differ from the clusters the user is authorized to access.
• Logs: Kite API access logs showing successful (HTTP 200) responses to /api/v1/overview for cluster names that do not match the requesting user's assigned roles or cluster permissions.
• Behavioral: A single user account querying the overview endpoint for multiple distinct cluster names in a short time window, suggesting enumeration of cluster inventory across unauthorized clusters.

Upgrade to Kite version 0.12.3, which is the patched release addressing this vulnerability. The fix should include adding an explicit rbac.CanAccessCluster(user, cs.Name) check in the GetOverview handler before any cluster data is queried, and/or moving the /api/v1/overview route registration to after api.Use(middleware.RBACMiddleware()) in routes.go. As a temporary workaround where upgrading is not immediately possible, restrict Kite access to trusted users only and monitor API logs for cross-cluster overview requests (GitHub Advisory, Kite Advisory).