CVE-2026-55636 — MEDIUM (5.7)

Vulnerability Description

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.

CVSS Score

5.7

MEDIUM

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

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction

REQUIRED

Scope

UNCHANGED

Confidentiality

LOW

Integrity

HIGH

Availability

LOW

Related Weaknesses (CWE)

CWE-863

References

FAQ

What is CVE-2026-55636?

CVE-2026-55636 is a vulnerability with a CVSS score of 5.7 (MEDIUM). 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 in...

How severe is CVE-2026-55636?

CVE-2026-55636 has been rated MEDIUM with a CVSS base score of 5.7/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-55636?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.