CVE-2026-55636: medium-severity vulnerability in projectcapsule capsule
Capsule: Incomplete fix of CVE-2026-30963: singular/plural typo leaves namespaces/finalize unprotected
Published
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13Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 5.7epss 0.4%
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:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:L/I:H/A:L
Affected products
projectcapsule · capsuleRelated CVEs — projectcapsule capsule
In the same product, most dangerous first.
CVE-2026-22872MEDIUMCapsule TenantResource RawItems Cluster-Scoped Resource Creation VulnerabilityEPSS 0.7%CVE-2026-61795MEDIUMCapsule: hostnameRegexHandler.OnUpdate validates stale (old) Tenant regex, allowing invalid AllowedHostnames regex to bypass webhook validationEPSS 0.6%CVE-2026-61794MEDIUMCapsule: Malformed ForbiddenAnnotations.Regex can bypass Tenant validation and trigger namespace admission panicEPSS 0.6%CVE-2024-39690HIGHCapsule tenant owner with "patch namespace" permission can hijack system namespacesEPSS 0.5%CVE-2025-55205CRITICALCapsule tenant owners with "patch namespace" permission can hijack system namespaces labelEPSS 0.5%CVE-2026-61672HIGHCapsule: Tenant owner bypasses Capsule's forbidden namespace/service/node label and annotation enforcementEPSS 0.3%