{"id":"CVE-2026-30963","aliases":["GHSA-2ww6-hf35-mfjm","GO-2026-5043"],"url":"https://o3.security/vulnerability/CVE-2026-30963","summary":"Capsule Namespace Hijacking via subresource","details":"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.","published":"2026-06-01T18:00:43.797Z","modified":"2026-08-12T03:51:09.094629282Z","cvss":{"score":3.9,"severity":"LOW","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L"},"epss":{"score":0.00203,"percentile":0.10572,"asOf":"2026-08-16"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"Go","name":"github.com/projectcapsule/capsule","fixedVersion":"0.13.0"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/projectcapsule/capsule/releases/tag/v0.13.0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/30xxx/CVE-2026-30963.json"},{"type":"ADVISORY","url":"https://github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6-hf35-mfjm"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-30963"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:09.094629282Z"}}