by Kastro
Paper/Archive/CVE-2026-122303

CVE-2026-122303

kyverno kyverno — Kyverno 1.17.0 before 1.19.2 Cross-Namespace Resource Overwrite via NamespacedMutatingPolicy

CVSS 9.9
critical.is priorityof 100
30
CVSS 9.9 (CNA)9.9 / 10 × 3029.7Not in CISA KEV+300.0No EPSS score.000 × 200.0No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
kyverno1.17.0 – < 1.19.21.19.2CNA

Scores by source

VulnCheck (CNA)9.9CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
VulnCheck (CNA)9.4CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H

References

advisorygithub.com/kyverno/kyverno/security/advisories/GHSA-jcw5-3wcg-fqx5writeupvulncheck.com/advisories/kyverno-1.17.0-before-1.19.2-cross-namespace-resource-overwrite-via-namespacedmutatingpolicy