Vulnerability in Kyverno
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 · last modified .
CVSS v3 metric
CVSS v3 base score 9.9 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (49.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.006 · newest: 0.006 · change: 0.000
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-5qq8-67g6-4h2w) (vendor-advisory)
- VulnCheck Advisory: kyverno before 1.19.1 Privilege Escalation via Policy apiCall urlPath (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100706?
- CVE-2026-100706 is a critical-severity vulnerability in Kyverno, classified under Unintended Proxy or Intermediary (Confused Deputy). CVSS score: 9.9/10. Published 2026-09-26.
- How severe is CVE-2026-100706?
- Critical severity. CVSS v3 base score is 9.9 out of 10.