{"id":"CVE-2026-55636","sourceIdentifier":"security-advisories@github.com","published":"2026-09-15T16:17:14.990","lastModified":"2026-09-30T17:51:56.193","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"Capsule is a multi-tenancy and policy-based framework for Kubernetes. From 0.13.0 until 0.13.6, charts/capsule/templates/configuration.yaml configures the validating webhook with namespace/finalize instead of the Kubernetes resource name namespaces/finalize. A user with namespaces/finalize RBAC can send a PUT request to /api/v1/namespaces/{namespace}/finalize, and the singular rule never matches the plural resource, so the validating webhook is not invoked and the user can change the namespace tenant label. matchPolicy: Equivalent does not compensate because it handles API group and version equivalence rather than resource-name errors. This vulnerability is fixed in 0.13.6."}],"affected":[{"source":"security-advisories@github.com","affectedData":[{"vendor":"projectcapsule","product":"capsule","versions":[{"version":">= 0.13.0, < 0.13.6","status":"affected"}]}]}],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:H/A:L","baseScore":5.7,"baseSeverity":"MEDIUM","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"HIGH","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"LOW","integrityImpact":"HIGH","availabilityImpact":"LOW"},"exploitabilityScore":0.9,"impactScore":4.7}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-09-15T17:38:16.677370Z","id":"CVE-2026-55636","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"weaknesses":[{"source":"security-advisories@github.com","type":"Secondary","description":[{"lang":"en","value":"CWE-863"}]}],"references":[{"url":"https://github.com/projectcapsule/capsule/commit/af2f37793e789b2301da8ed8dfb52ab60affebb6","source":"security-advisories@github.com"},{"url":"https://github.com/projectcapsule/capsule/pull/1966","source":"security-advisories@github.com"},{"url":"https://github.com/projectcapsule/capsule/releases/tag/v0.13.6","source":"security-advisories@github.com"},{"url":"https://github.com/projectcapsule/capsule/security/advisories/GHSA-gwxr-7h77-7777","source":"security-advisories@github.com"}]}