Description
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.
Affected products
projectcapsule: capsule
References3
- github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6… ExploitMitigationVendor Advisory
- github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6… ExploitMitigationVendor Advisory
- github.com/projectcapsule/capsule/releases/tag/v0.13.0 ProductRelease Notes
Metrics
- CVSS 3.1
-
2.7
LOW
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N - EPSS — exploit probability
- 0% percentile: 12 · as of 15 November 2026
- CWE
- CWE-20
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