CVE-2026-22039: Kyverno Policy apiCall Authorization Boundary Bypass
Kyverno versions before 1.15.3 and from 1.16.0 before 1.16.3 allow a user who can create namespaced Policies to make the admission controller ServiceAccount perform Kubernetes API requests beyond the policy's namespace. The record rates the issue critical, with a CVSS 3.1 base score of 9.9, and classifies it as CWE-269. Fixed releases are 1.15.3 and 1.16.3.
Overview
Kyverno is a policy engine used by cloud native platform engineering teams. According to the record, versions before 1.15.3 and from 1.16.0 before 1.16.3 contain an authorization boundary bypass in the apiCall feature of namespaced Policy resources. The GitHub security advisory and the patch commit are referenced in the record.
Impact
- Cross-namespace reads, for example of ConfigMaps and, where permitted, Secrets.
- Cluster-scoped or cross-namespace writes, for example creation of ClusterPolicies.
- Breakdown of namespace isolation, because requests run under the Kyverno admission controller ServiceAccount identity.
The record assigns a CVSS 3.1 base score of 9.9 (critical) with the vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
Affected products and versions
The record lists Kyverno Kyverno as affected in versions below 1.15.3 and in versions from 1.16.0 below 1.16.3. The fixed releases named in the record are 1.15.3 and 1.16.3. The record does not provide information about other release lines.
Exploitation status
The record shows the vulnerability is not listed in the CISA KEV catalog, and no EPSS or SSVC data is present. No confirmed active exploitation appears in the sources consulted for this analysis.
Remediation and mitigation
- Upgrade Kyverno to 1.15.3 or 1.16.3, or to the corresponding fixed release in the same branch.
- Review which identities can create namespaced Policy resources and limit that permission to trusted roles.
- Review existing Policies that use apiCall and context variable substitution in request paths.
- Review the RBAC granted to the Kyverno admission controller ServiceAccount and reduce it to what is strictly required.
- Consult the vendor advisory for the mitigation guidance it provides.
Detection guidance
- Audit Kubernetes API logs for requests made by the Kyverno admission controller ServiceAccount that target namespaces other than the namespace of the originating Policy.
- Monitor creation of ClusterPolicy or other cluster-scoped objects by unexpected sources.
- The record contains no detection signatures, so these are high-level suggestions to be adapted to local logging.
Limitations of the available information
- The record does not describe how practical exploitation is in any specific cluster configuration.
- KEV status is shown as not listed, while EPSS and SSVC values are absent.
- The contents of the patch commits were not analyzed beyond their presence in the record.
- Whether other release lines are affected is unknown from the record.
Frequently asked questions
What is the core problem in CVE-2026-22039?
Users who can create namespaced Kyverno Policies can cause the Kyverno admission controller to make Kubernetes API requests under its own ServiceAccount identity, which can reach beyond the policy namespace.
Which versions are fixed?
According to the record, the fixed releases are 1.15.3 and 1.16.3. Versions below 1.15.3, and versions from 1.16.0 below 1.16.3, are listed as affected.
Is this vulnerability known to be actively exploited?
The record shows it is not listed in CISA KEV, and no confirmed active exploitation appears in the sources consulted for this analysis.
This analysis was drafted with AI assistance from verified source data and automatically checked against it.