Vulnerability · Published Nov 5, 2026 · Assigned by VulnCheck

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

Critical 9.9

In plain English

A critical-severity missing authorization in kyverno from kyverno. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities).

Severity (CVSS 3.1)9.9Critical

Exploit odds (30 days)0.3%top 73.7% of all CVEs

Exploited in the wildNo reportsnot in CISA KEV

Attack toolingNoneno public tooling known

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.

Affected products (as reported)

Vendor	Product	Versions
kyverno	kyverno	1.17.0 – before 1.19.2

Weakness: CWE-862 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

References

GitHub Security Advisory (GHSA-jcw5-3wcg-fqx5) vendor-advisory
VulnCheck Advisory: Kyverno 1.17.0 before 1.19.2 Cross-Namespace Resource Overwrite via NamespacedMutatingPolicy third-party-advisory