GHSA-jr6p-8pjj-mfx6 Capsule has an incomplete fix of CVE-2026-22872: TenantResource RawItems and Generators still allow cluster-scoped resource creation (cross-tenant privilege escalation)
SummaryCVE-2026-22872 (GHSA-qjjm-7j9w-pw72) reported that a Tenant Owner could create cluster-scoped resources
(e.g. `ClusterRole`, `ValidatingWebhookConfiguration`) through a `TenantResource`, because the controller
applies them with its cluster-admin ServiceAccount and `SetNamespace` is ineffective for cluster-scoped
kinds. The v0.13.0 fix added a cluster-scope rejection guard, but **only on the NamespacedItems selection
path** (`ResourceReference.LoadResources` -> `IsNamespacedGVK`, error `"cluster-scoped kind ... is not
allowed"`). The **RawItems create path — the exact vector the original advisory named — and the Generators
path were not given this guard.** The vulnerability therefore persists in all releases **v0.13.0 through
v0.13.7** and on trunk HEAD (`8d89d6865d`).DetailsTenantResource reconcile flow:`internal/controllers/resources/namespaced.go` `reconcile()` obtains the apply client via `loadClient()`;
by default (impersonation off, no `Spec.ServiceAccount`) this is the manager client whose SA is bound to
cluster-admin (`charts/capsule/templates/rbac.yaml:488-501`, `{fullname}-manager-rolebinding` ->
roleRef cluster-admin).`Collector.Collect()` (`collect.go`) processes `spec.RawItems` via `handleRawItem` and `spec.Generators`
via `handleGeneratorItem`.`handleRawItem` (`collect.go:406-425`, trunk HEAD — byte-identical to v0.13.0):`handleGeneratorItem` (`collect.go:382-404`) is the same: it only `SetNamespace`s on rendered objects.The accumulated objects flow to `pkg/api/processor/processor_func.go` `Reconcile()` -> `Apply()` ->
`clt.PatchApply(ctx, c, obj, ...)` (line 167/378) with **no scope check at any point**.By contrast, `CollectNamespacedItems` (`collect.go:308`) calls `item.LoadResources(..., allowClusterScoped=false)`,
and `pkg/template/reference.go:105-107` enforces:So the guard the fix added is real, but it sits on a different (selection) path than the one the CVE
described (RawItems create path). For cluster-scoped kinds, `SetNamespace` is ignored by the Kubernetes API
server, so the object is created cluster-wide by the cluster-admin client.**Parent-fix diff confirmation:** in v0.12.4 the RawItems handler in `processor.go` was the vulnerable code
(`obj.SetNamespace(ns.Name)` then `createOrUpdate` via `r.client`). v0.13.0 refactored this into
`collect.go` `handleRawItem` but left it without the new guard.Proof of ConceptA self-contained in-process Go test (`incompletefix_poc_test.go`), run against trunk HEAD with go1.26.4,
proves the asymmetry:`TestRawItemPath_NoClusterScopeGuard`: feeds a `ClusterRole` rawItem to `handleRawItem` -> object returned
unchanged, no rejection (PASS).`TestNamespacedItemsPath_HasClusterScopeGuard`: feeds the same `ClusterRole` kind to
`LoadResources(allowClusterScoped=false)` -> rejected with
`"cluster-scoped kind rbac.authorization.k8s.io/v1/ClusterRole is not allowed"` (PASS).End-to-end (cluster) reproduction:Deploy capsule (default Helm) with `rbac.resources.create=true` (the opt-in that exposes TenantResources
to tenant owners; the configuration the original CVE applies to).As a Tenant Owner, create in a tenant namespace:Observe the cluster-scoped ClusterRole `tenant-escalation` is created by the cluster-admin controller,
despite the tenant owner lacking cluster RBAC to create it. Swap in `ValidatingWebhookConfiguration`
to intercept/exfiltrate cluster-wide Secrets.ImpactA Tenant Owner (namespace-scoped) escalates to cluster-admin-equivalent privileges and can compromise all
tenants and the cluster control plane. Identical impact to CVE-2026-22872; the v0.13.0 remediation does not
close the RawItems/Generators vector.RemediationApply the same `IsNamespacedGVK` / `allowClusterScoped` rejection inside `handleRawItem` and
`handleGeneratorItem` — or centrally in `Collector.AddToAccumulation` / `processor.Apply` — so the create
path enforces the same cluster-scope policy as the selection path. (`GlobalTenantResource` shares the path
but is not a privesc — cluster-admin-only to create.)
CVSS v3.1 score: 6.6