Kubewarden: RBAC Reconnaissance via unchecked can_i host capability call
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- Low · None · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-862.
Summary
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 .
Why it matters now
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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| kubewarden | kubewarden-controller | before 1.35.0 | 1.35.0 | Patch available | CNA |
| — | github.com/kubewarden/kubewarden-controller (Go) | before 1.35.0 | 1.35.0 | Patch available | GHSA-wqcw-g35j-j578 |
- kubewarden-controller Vendorkubewarden Affected before 1.35.0 Fixed in 1.35.0 Patch available CNA
- github.com/kubewarden/kubewarden-controller (Go) Vendor— Affected before 1.35.0 Fixed in 1.35.0 Patch available GHSA-wqcw-g35j-j578
Remediation
- Fix · CNA kubewarden-controller (kubewarden) Fixed in 1.35.0
- Fix · GHSA-wqcw-g35j-j578 github.com/kubewarden/kubewarden-controller (Go) Fixed in 1.35.0 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-42541
- 2026-10-03 Alias added: GHSA-wqcw-g35j-j578
References
Other 6
- https://github.com/kubewarden/adm-controller/security/advisories/GHSA-wqcw-g35j-j578
- https://github.com/kubewarden/kubewarden-controller/security/advisories/GHSA-wqcw-g35j-j578
- https://github.com/kubewarden/docs/pull/737
- https://github.com/kubewarden/kubewarden-controller/pull/1693
- https://docs.kubewarden.io/howtos/policy-servers/namespaced-policies-capabilities
- https://github.com/kubewarden/kubewarden-controller
More kubewarden vulnerabilities
- TI-2025-18119 The kubewarden-controller AdmissionPolicy and AdmissionPolicyGroup policies can be used to alter PolicyReport resources CVSS 3.1MEDIUM 6.5
- TI-2026-83428 Case-sensitive registry check in Kubewarden trusted-repos-policy CVSS 3.1MEDIUM 6.3
- TI-2025-18501 kubewarden-controller has an Information leak via AdmissionPolicyGroup Resource CVSS 3.1MEDIUM 4.3
Sources
- CVE-2026-42541 · CVE Program
- CVE-2026-42541 · NVD
- FIRST EPSS
- GHSA-wqcw-g35j-j578 · GitHub Advisory Database · CC BY 4.0
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