Vulnerability · Published May 12, 2026 · Assigned by GitHub_M
CVE-2026-42541Kubewarden: RBAC Reconnaissance via unchecked can_i host capability call
Medium 4.3
In plain English
A medium-severity missing authorization in kubewarden-controller from kubewarden. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Kubewarden is a policy engine for Kubernetes. Prior to , An attacker with privileged AdmissionPolicy or AdmissionPolicyGroup create permissions (which isn't the default) can craft a policy that makes use of the can_i host callback. The callback issues a SubjectAccessReview (SAR) requests to enumerate RBAC permissions of any user or service account across the cluster. can_i does not perform that check to enforce the context-aware allow-list and forwards the request directly to the callback handler, which executes a real SubjectAccessReview using policy-server privileges. This creates a policy-level authorization gap: can_i is effectively usable even when the policy has no context-aware resource grant. This is an information disclosure / reconnaissance issue, and not direct workload data exfiltration. The attacker learns permission information, such as whether specific service accounts can "get secrets", "create pods", or "bind clusterroles" in chosen namespaces. This vulnerability is fixed in .
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Go | github.com/kubewarden/kubewarden-controller | 1.35.0 | GHSA-wqcw-g35j-j578 |
| Go | github.com/kubewarden/kubewarden-controller | 1.35.0 | GO-2026-5716 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| kubewarden | kubewarden-controller | < 1.35.0 |
Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N