CVE-2026-100706

kyverno before 1.19.1 fails to properly validate URL-encoded path segments in Policy apiCall urlPath, allowing namespace tenants to bypass the per-namespace clamp and create objects in other namespaces as the admission-controller ServiceAccount. Attackers can exploit this by using percent-encoded directory traversal sequences to create MutatingWebhookConfiguration objects cluster-wide or PolicyException objects in the kyverno namespace, enabling privilege escalation to cluster admin.

  • Published Sep 26, 2026
  • CVSS 9.4 critical
  • 0.6% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2026-100706 at the National Vulnerability Database