Kyverno 1.17.0 before 1.19.2 Cross-Namespace Write via NamespacedMutatingPolicy mutateExisting

Summary

Kyverno from 1.17.0 before 1.19.2 contains a missing authorization vulnerability in the mutate-existing background processor that allows namespaced tenants to modify resources outside their namespace. Attackers can create a NamespacedMutatingPolicy targeting Namespace objects or victim-namespace resources via CEL expressions, making the background-controller ServiceAccount strip Pod Security labels cluster-wide.

Remediation

1. Inventory every kyverno kyverno deployment, including staging.
2. Upgrade kyverno kyverno to 1.19.2.
3. Confirm the running version after the upgrade.

References

• Advisoryhttps://github.com/kyverno/kyverno/security/advisories/GHSA-vm98-8c25-h274
• Advisoryhttps://www.vulncheck.com/advisories/kyverno-1.17.0-before-1.19.2-cross-namespace-write-via-namespacedmutatingpolicy-mutateexisting