Capsule Namespace Hijacking via subresource_CVE-2026-30963

3.9 / 10

LOW

CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L

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.

Basic Information

ID CVE-2026-30963

Source GitHub_M

Published Jun 1, 2026 at 18:00

Affected Product

Vendor projectcapsule

Product capsule

Version < 0.13.0

Affected Versions projectcapsule capsule < 0.13.0

CWE Classification

CWE-20

References

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    "published": "2026-06-01T18:00:43.797Z",
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