CVE-2026-122303 Kyverno 1.17.0 before 1.19.2 Cross-Namespace Resource Overwrite via NamespacedMutatingPolicy

What is CVE-2026-122303?

CVE-2026-122303 is a critical vulnerability in kyverno, published on 5 Nov 2026.

Official description

Kyverno from 1.17.0 before 1.19.2 contains an authorization bypass vulnerability that allows namespace tenants to overwrite resources in other namespaces via NamespacedMutatingPolicy mutate-existing targetMatchConstraints.expression. Attackers can return a CEL map literal fabricating a target with an attacker-chosen metadata.namespace, causing the privileged background controller to overwrite Secrets, Deployments, or policies cluster-wide.

Weakness: CWE-862

Which versions are affected by CVE-2026-122303?

It affects 1 product.

Products include Kyverno.

How do I fix CVE-2026-122303?

No fix has been published for CVE-2026-122303 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-122303 being exploited?

There is no known exploitation of CVE-2026-122303 in the wild and no public exploit code.

Other vulnerabilities in kyverno

• CVE-2026-22039 Kyverno Cross-Namespace Privilege Escalation via Policy apiCall Critical 10.0
• CVE-2026-4789 CVE-2026-4789 Critical 9.8
• CVE-2026-122304 Kyverno 1.17.0 before 1.19.2 Privilege Escalation via CleanupPolicy Context Loader Critical 9.4
• CVE-2026-122310 Kyverno 1.19.1 before 1.19.2 Privilege Escalation via Policy apiCall urlPath Critical 9.4
• CVE-2026-122311 Kyverno 1.16.0 before 1.19.2 Path Traversal in Namespaced CEL Policies via resource argument Critical 9.4

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• GitHub advisory
• How this page is made

Also known as GHSA-jcw5-3wcg-fqx5, GHSA-m6w5-f9j8-9pjp.