GO · AUGUST 2026 · EARLY WARNING

Kyverno v1.18.1 Vulnerability: Arbitrary Namespace Resource Generation

EARLY WARNING · UNCONFIRMED. This page describes a developing threat that 0Day surfaced from early signals and has not yet independently confirmed. Details may change. Always verify against the primary sources before acting.
Severity
HIGH
Affected component
kyverno (go)
Affected versions
>= 1.18.0, <= 1.18.1
Patched version
Not yet available
GHSA-79GF-7FRW-68M9

An early warning has been issued for a high-severity vulnerability in Kyverno v1.18.1. This vulnerability allows a tenant to generate resources in any namespace by passing an arbitrary namespace string to the CEL generator.apply(namespace, resources) function.

What happened

In Kyverno v1.18.1, a tenant who can create a NamespacedMutatingPolicy in their own namespace can instruct the admission controller to generate resources in any namespace. This is achieved by passing an arbitrary namespace string to the CEL generator.apply(namespace, resources) function. The background controller then creates RoleBindings in any namespace, including kube-system. This vulnerability is tracked as GHSA-79GF-7FRW-68M9 and CVE-2026-84200 with a CVSS score of 9.0, indicating critical severity.

The vulnerability affects Kyverno versions 1.18.0 to 1.18.1. It is under investigation and has not yet been exploited in the wild. The recommended action is to upgrade to a version of Kyverno that fixes this issue and to review and restrict permissions for creating NamespacedMutatingPolicy resources.

What to do about it

How 0Day would have caught this

MATCHED TO YOUR ACTUAL DEPENDENCY GRAPH0Day matches every incoming threat signal against your GitHub organization’s full dependency graph, including transitive dependencies. If kyverno is anywhere in your dependency tree, the engineers who own the affected repositories get a push alert the moment it is flagged — no manual audit to remember to run.

Read how this differs from waiting on a scanner to catch a known advisory, or see the exact, read-only access 0Day needs to do this for an organization.

Frequently asked questions

Am I affected?

You are affected if you are using Kyverno versions 1.18.0 to 1.18.1.

What should I do right now?

Upgrade to a version of Kyverno that fixes this issue and review and restrict permissions for creating NamespacedMutatingPolicy resources.

Is there an official fix available?

No official fix has been published yet. Monitor the primary sources for updates.

Sources

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