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BIT-kyverno-2026-41068 — Kyverno: Cross-Namespace Read Bypasses RBAC Isolation (CVE-2026-22039 Incomplete Fix)

Affected: Bitnami: kyverno

Kyverno is a policy engine designed for cloud native platform engineering teams. The patch for CVE-2026-22039 fixed cross-namespace privilege escalation in Kyverno's `apiCall` context by validating the `URLPath` field. However, the ConfigMap context loader has the identical vulnerability — the `configMap.namespace` field accepts any namespace with zero validation, allowing a namespace admin to read ConfigMaps from any namespace using Kyverno's privileged service account. This is a complete RBAC bypass in multi-tenant Kubernetes clusters. An updated fix is available in version 1.17.2.

EUVD-2026-292912

fkie_cve-2026-41068

GHSA-cvq5-hhx3-f99p — Kyverno: Cross-Namespace Read Bypasses RBAC Isolation (CVE-2026-22039 Incomplete Fix)

Affected: Go: github.com/kyverno/kyverno

### Summary

CVE-2026-22039 fixed cross-namespace privilege escalation in Kyverno's `apiCall` context by validating the `URLPath` field. However, the **ConfigMap context loader has the identical vulnerability** — the `configMap.namespace` field accepts any namespace with zero validation, allowing a namespace admin to read ConfigMaps from any namespace using Kyverno's privileged service account. This is a complete RBAC bypass in multi-tenant Kubernetes clusters.

### Details

**Root cause:** The CVE-2026-22039 fix in `pkg/engine/apicall/apiCall.go` (lines 73-83) validates that `URLPath` references only the policy's own namespace using regex. However, the ConfigMap context loader at `pkg/engine/context/loaders/configmap.go` performs **no namespace validation** on the `namespace` field.

**Code path comparison:**

| | CVE-2026-22039 (fixed) | This vulnerability (unfixed) | |--|---|---| | **Location** | `apiCall.URLPath` field | `configMap.namespace` field | | **Code path** | `apicall.Fetch()` → namespace regex validation | `configmap.NewConfigMapLoader()` → no validation | | **Root cause** | Variable substitution + missing validation | Same pattern, still unpatched |

**Exploit mechanism:** 1. Namespace admin creates a Kyverno Policy in their namespace (standard RBAC) 2. Policy uses `context.configMap.namespace: "victim-ns"` to reference another namespace 3. Kyverno's admission controller service account (has cluster-wide `view` role) fetches the ConfigMap 4. Policy mutates a t…