{"id":"CVE-2026-30963","state":"PUBLISHED","title":"Capsule Namespace Hijacking via subresource","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.","publishedAt":"2026-06-01T18:00:43.797Z","updatedAt":"2026-06-02T14:06:11.444Z","severity":{"score":3.9,"label":"Low","version":"3.1","vector":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["projectcapsule capsule"],"affected":[{"vendor":"projectcapsule","product":"capsule","versions":[{"version":"< 0.13.0","status":"affected"}]}],"references":["https://github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6-hf35-mfjm","https://github.com/projectcapsule/capsule/releases/tag/v0.13.0"],"weaknesses":["CWE-20"],"ingestedAt":"2026-10-29T20:11:31.369Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/30xxx/CVE-2026-30963.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-30963","state":"PUBLISHED","datePublished":"2026-06-01T18:00:43.797Z","dateUpdated":"2026-06-02T14:06:11.444Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-07T17:53:48.814Z"},"containers":{"cna":{"title":"Capsule Namespace Hijacking via subresource","descriptions":[{"lang":"en","value":"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":[{"vendor":"projectcapsule","product":"capsule","versions":[{"version":"< 0.13.0","status":"affected"}]}],"references":[{"url":"https://github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6-hf35-mfjm","name":"https://github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6-hf35-mfjm","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/projectcapsule/capsule/releases/tag/v0.13.0","name":"https://github.com/projectcapsule/capsule/releases/tag/v0.13.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":3.9,"baseSeverity":"LOW","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"HIGH","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:H/PR:H/UI:R/S:U/C:L/I:L/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","lang":"en","description":"CWE-20: Improper Input Validation","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-06-01T18:00:43.797Z"},"source":{"advisory":"GHSA-2ww6-hf35-mfjm","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/projectcapsule/capsule/security/advisories/GHSA-2ww6-hf35-mfjm","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-02T14:04:59.231575Z","id":"CVE-2026-30963","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-02T14:06:11.444Z"}}]}}}