by Kastro
Paper/Archive/CVE-2026-124440

CVE-2026-124440

kyverno kyverno — Kyverno 1.19.1 Privilege Escalation via apiCall Namespace Clamp Bypass

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 1.19.1 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.

Affected

ProductAffectedFixed inSource
kyverno1.19.1 – < 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-39w8-hv5g-f73wwriteupvulncheck.com/advisories/kyverno-1.19.1-privilege-escalation-via-apicall-namespace-clamp-bypass