CVE-2026-54523Escalación de privilegios entre namespaces en Kyverno
Kyverno is a policy engine designed for cloud native platform engineering teams. From 1.18.0 until 1.18.2, the NamespacedMutatingPolicy CEL compiler exposes the generator library to matchConditions, allowing a namespace-scoped policy to invoke generator.apply(namespace, resources) with an arbitrary target namespace. The validation in pkg/cel/policies/mpol/validate.go checks that the policy compiles but does not enforce namespace scope, and GenerateResources in pkg/cel/libs/context.go does not reject the cross-namespace target. A user who can create NamespacedMutatingPolicy objects in one namespace can cause the admission controller, operating with cluster-wide privileges, to create ConfigMaps, NetworkPolicies, Secrets, RoleBindings, and other resources in another namespace, enabling unauthorized modification and potential privilege escalation. This issue is fixed in version 1.18.2.
Ver en NVDAnálisis
A critical vulnerability in Kyverno allows attackers with local namespace permissions to create resources like Secrets, ConfigMaps, or RoleBindings in any other namespace. This effectively breaks Kubernetes namespace isolation and allows for full cluster privilege escalation.
Roles relevantes
Severidad
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:NCWE-862EPSS
Sin puntaje EPSS aún (CVE muy reciente).
Descripción técnica
Kyverno is a policy engine designed for cloud native platform engineering teams. From 1.18.0 until 1.18.2, the NamespacedMutatingPolicy CEL compiler exposes the generator library to matchConditions, allowing a namespace-scoped policy to invoke generator.apply(namespace, resources) with an arbitrary target namespace. The validation in pkg/cel/policies/mpol/validate.go checks that the policy compiles but does not enforce namespace scope, and GenerateResources in pkg/cel/libs/context.go does not reject the cross-namespace target. A user who can create NamespacedMutatingPolicy objects in one namespace can cause the admission controller, operating with cluster-wide privileges, to create ConfigMaps, NetworkPolicies, Secrets, RoleBindings, and other resources in another namespace, enabling unauthorized modification and potential privilege escalation. This issue is fixed in version 1.18.2.
Referencias
- https://github.com/kyverno/kyverno/commit/0919553c0ea1904f8d891280c92018da97946a06
- https://github.com/kyverno/kyverno/commit/5164bcdeda5b57678bc2d7a03ecc2cbb02982dae
- https://github.com/kyverno/kyverno/pull/16238
- https://github.com/kyverno/kyverno/releases/tag/v1.18.2
- https://github.com/kyverno/kyverno/security/advisories/GHSA-79gf-7frw-68m9
- https://github.com/kyverno/sdk/commit/6573937441443e1ba5af9fbb28d5c0f20297f9df
- https://github.com/kyverno/kyverno/security/advisories/GHSA-79gf-7frw-68m9