# CVE-2026-100706: Kyverno Policy apiCall URL path validation bypass

Source: https://junglewise.ai/threats/cve-2026-100706-kyverno-before-1-19-1-fails-to-properly-validate-url-encoded  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-26. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-100706 · Severity: critical · CVSS 9.9 · Published 2026-09-26

Kyverno is a Kubernetes policy engine that enforces security and compliance rules. A flaw in URL path validation allows authenticated namespace users to bypass restrictions and create configuration objects cluster-wide, which can be leveraged to escalate privileges to cluster administrator. An attacker can register malicious webhook configurations to intercept and modify Kubernetes objects across all namespaces.

Technologies: [Kyverno](https://junglewise.ai/threats/technologies/kyverno). Vendors: [Kyverno](https://junglewise.ai/threats/vendors/kyverno).

## Quick answers

**Is CVE-2026-100706 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-100706 being exploited in the wild.

**How severe is CVE-2026-100706?** Critical severity, with a CVSS score of 9.9, published 26 September 2026.

**Which products and versions are affected?** Kyverno before 1.19.1.

**Is there a fix for CVE-2026-100706?** A patch was published on 2026-09-10: version 1.19.1 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-100706 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-100706?** Check whether you run Kyverno at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

Kyverno fails to properly validate percent-encoded path segments in Policy apiCall urlPath, allowing namespace-confined users to traverse beyond their namespace boundary. By injecting %2e%2e segments, an attacker can reach cluster-scoped API endpoints and create MutatingWebhookConfiguration or PolicyException objects as the admission-controller ServiceAccount. This enables privilege escalation to cluster admin through webhook-based object rewriting or policy exception bypass.

## Affected products

- Kyverno Kyverno before 1.19.1

## Timeline

- 2026-09-10: disclosed
- 2026-09-10: patched: version 1.19.1

## References

- [https://github.com/kyverno/kyverno/security/advisories/GHSA-5qq8-67g6-4h2w](https://github.com/kyverno/kyverno/security/advisories/GHSA-5qq8-67g6-4h2w)
- [https://www.vulncheck.com/advisories/kyverno-before-1.19.1-privilege-escalation-via-policy-apicall-urlpath](https://www.vulncheck.com/advisories/kyverno-before-1.19.1-privilege-escalation-via-policy-apicall-urlpath)

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- [Kyverno authorization bypass in generate rule validation](https://junglewise.ai/threats/cve-2026-124441-kyverno-before-1-19-2-contains-an-authorization-bypass)
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