CVE-2026-30963
Capsule is a multi-tenancy and policy-based framework for Kubernetes.
Does this matter?
Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 2.7 LOWCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
- EPSS
- 0.22% probability · 12th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-20
- Affected
- projectcapsule/capsule
- Source
- security-advisories@github.com
References
- https://github.com/projectcapsule/capsule/releases/tag/v0.13.0Product, Release Notes
- https://github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6-hf35-mfjmExploit, Mitigation, Vendor Advisory
- https://github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6-hf35-mfjmExploit, Mitigation, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.