CVE-2026-122303

Critical

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.

SeverityCritical

CVSS9.9

Exploit probability26. percentile0.3%

ProductKyverno

PublishedNov 5, 2026

First seenNov 5, 2026

Weakness typeCWE-862Missing authorization

How to fix

Update

kyverno kyverno1.19.2 or later

Vendor advisories

github.com/kyverno/kyverno/security/advisories/GHSA-jcw5-3wcg-fqx5

Affected products

Product	Affected versions	Fixed in
kyverno kyverno	1.17.0 ≤ v < 1.19.2	1.19.2

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