Description
Kyverno is a policy engine designed for cloud native platform engineering teams. Prior to versions 1.18.0-rc1, 1.17.2-rc1, and 1.16.4, Kyverno's apiCall feature in ClusterPolicy automatically attaches the admission controller's ServiceAccount token to outgoing HTTP requests. The service URL has no validation — it can point anywhere, including attacker-controlled servers. Since the admission controller SA has permissions to patch webhook configurations, a stolen token leads to full cluster compromise. Versions 1.18.0-rc1, 1.17.2-rc1, and 1.16.4 patch the issue.
Affected products
kyverno: kyverno
References5
- github.com/kyverno/kyverno/security/advisories/GHSA-f9g8-6ppc-p… ExploitVendor Advisory
- github.com/kyverno/kyverno/security/advisories/GHSA-f9g8-6ppc-p… ExploitVendor Advisory
- github.com/kyverno/kyverno/commit/bc4f91c4801b1eaa2edc0a14e2f1b… Patch
- github.com/kyverno/kyverno/commit/c2eab00033e635bda4e4efb58c1b4… Patch
- github.com/kyverno/kyverno/commit/f70e8ac1e7acd2e3844f9553e4a88… Patch
Metrics
- CVSS 3.1
-
9.1
CRITICAL
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 1% percentile: 47 · as of 13 November 2026
- CWE
- CWE-200CWE-918
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.