CVE-2026-55636

medium

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.

References

https://github.com/projectcapsule/capsule/security/advisories/GHSA-gwxr-7h77-7777

https://github.com/projectcapsule/capsule/releases/tag/v0.13.6

https://github.com/projectcapsule/capsule/pull/1966

https://github.com/projectcapsule/capsule/commit/af2f37793e789b2301da8ed8dfb52ab60affebb6

https://euvd.enisa.europa.eu/vulnerability/EUVD-2026-78670

Details

Source: Mitre, NVD

Published: 2026-09-15

Updated: 2026-09-15

Risk Information

CVSS v2

Base Score: 7.3

Vector: CVSS2#AV:N/AC:L/Au:M/C:P/I:C/A:P

Severity: High

CVSS v3

Base Score: 5.7

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

Severity: Medium

EPSS

EPSS: 0.00277