CVE-2026-122313: Kyverno 1.17.0 before 1.19.2 Cross-Namespace Privilege Escalation via NamespacedMutatingPolicy
Kyverno from 1.17.0 before 1.19.2 contains a privilege escalation vulnerability that allows namespace-scoped tenants to modify resources in other namespaces through NamespacedMutatingPolicy targetMatchConstraints.expression CEL output lacking namespace checks. Attackers can emit a literal target such as another tenant's RoleBinding, which the cluster-wide background controller then mutates to add attacker subjects or alter Roles, NetworkPolicies, and ConfigMaps.
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Kyvernoto a version that resolves this vulnerability.Fixed in 1.19.2
Event History
Frequently Asked Questions
Who is realistically exposed to this issue?
Clusters running Kyverno versions from 1.17.0 before 1.19.2 are exposed where namespace-scoped tenants can create or control NamespacedMutatingPolicy resources. The impact is especially significant in multi-tenant clusters because a tenant can target resources belonging to another namespace.
What does an attacker need to exploit it?
An attacker needs namespace-scoped access sufficient to use a NamespacedMutatingPolicy and provide a targetMatchConstraints.expression CEL output. They can supply a literal target for a resource in another namespace, which is then processed by the cluster-wide background controller.
What resources could be modified across namespaces?
The described attack can mutate another tenant's RoleBinding to add attacker subjects or change roles. It can also alter Roles, NetworkPolicies, and ConfigMaps in other namespaces.
How can I determine whether my cluster may be affected?
Check whether Kyverno is running a version from 1.17.0 before 1.19.2 and whether untrusted or tenant-scoped users can create or manage NamespacedMutatingPolicy resources. Review those policies for targetMatchConstraints.expression values that emit literal targets referring to resources outside the policy owner's namespace.