Vulnerability in Kyverno
CVE-2026-124440
Kyverno from 1.19.1 before 1.19.2 contains an authorization bypass vulnerability in the apiCall namespace clamp that allows namespace tenants to issue cross-namespace and cluster-scoped API requests by appending malformed percent-escapes to urlPath. Attackers can create namespaced Policies whose apiCall runs as the admission-controller ServiceAccount to read other namespaces' resources and create mutating webhooks, escalating to cluster admin.
Published .
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
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-39w8-hv5g-f73w) (vendor-advisory)
- VulnCheck Advisory: Kyverno 1.19.1 Privilege Escalation via apiCall Namespace Clamp Bypass (third-party-advisory)
Frequently asked questions
- What is CVE-2026-124440?
- CVE-2026-124440 is a critical-severity vulnerability in Kyverno, classified under Unintended Proxy or Intermediary (Confused Deputy). CVSS score: 9.9/10. Published 2026-11-08.
- How severe is CVE-2026-124440?
- Critical severity. CVSS v3 base score is 9.9 out of 10.