Bug 2541821 (CVE-2026-100706)

Summary: CVE-2026-100706 github.com/kyverno/kyverno: kyverno before 1.19.1 Privilege Escalation via Policy apiCall urlPath
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: gbenhaim, niyer, twaugh
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in Kyverno. An authenticated user with namespace-level permissions can achieve privilege escalation to cluster administrator by supplying encoded path traversal sequences within policy requests. This vulnerability allows an attacker to bypass namespace isolation controls and create unauthorized resources across the cluster using the elevated permissions of the admission controller service account.
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Description OSIDB Bzimport 2026-09-26 13:32:45 UTC 
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.