Threat Intelligence Database

CVE-2026-65835 is a medium severity vulnerability in projectcapsule's capsule framework affecting versions prior to 0.13.8. It involves improper privilege management where tenant owners could create cluster-scoped resources due to incomplete enforcement of resource scope restrictions. The issue was fixed in version 0.13.8.

Capsule is a multi-tenancy and policy-based framework for Kubernetes. Prior to 0.13.8, CapsuleConfiguration.Spec.NodeMetadata.ForbiddenLabels.Regex and CapsuleConfiguration.Spec.NodeMetadata.ForbiddenAnnotations.Regex were not validated by the configuration admission webhook, allowing a Cluster Admin to store a malformed regex that later reached regexp.MustCompile in pkg/api/forbidden_list.go through internal/webhook/node/user_metadata.go and crashed the node admission webhook on Node create, update, or patch requests. This issue is fixed in version 0.13.8.

Capsule is a multi-tenancy and policy-based framework for Kubernetes. To defend against namespace hijacking achieved through update/patch operations on namespaces, Capsule uses a webhook to validate update requests targeting namespaces. However, in Kubernetes, the namespace/finalize and namespace/status subresource APIs can also modify various fields of a namespace, including the metadata field. Prior to version 0.13.0, the webhook does not define interception rules for these subresources. As a result, if a tenant administrator has permission to modify namespace/status or namespace/finalize, they can successfully perform namespace hijacking. Version 0.13.0 fixes the issue. Another mitigation is to add two subresources (namespaces and snamespaces/status with namespace/finalize within it) to the resources list in the ValidatingWebhookConfiguration rules.

Capsule is a multi-tenancy and policy-based framework for Kubernetes. The Capsule Controller runs with cluster-admin privileges. Although the TenantResource RawItems processing logic forcibly sets the namespace, this is ineffective for cluster-scoped resources. Prior to version 0.13.0, tenant administrators can leverage the Controller's elevated privileges to create cluster-scoped resources (such as ClusterRole and ValidatingWebhookConfiguration) that they cannot create directly, achieving cross-tenant privilege escalation and cluster-level attacks. The attack vector has a few limiting factors. This attack requires Tenant Owner privileges and requires Capsule Controller running with cluster-admin privileges (default configuration). Additionally, some clusters may have additional admission controllers blocking malicious resources. Version 0.13.0 patches this issue.