Description
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.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| kyverno | kyverno | < 1.19.1 | 1.19.1 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | kyverno-1.17 +1 | No fix yet | — |
Advisories 1
- WID-SEC-2026-3285 Kyverno: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 27, 2026
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