CVE-2026-100704: Kyverno before 1.19.1 ImageValidatingPolicy Exception Bypass

Severity: high (CVSS 7.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-26 · updated 2026-09-30
Weakness: CWE-863

Description

Kyverno is a policy engine for Kubernetes. In versions 1.14.0 through 1.19.0, the ImageValidatingPolicy (policies.kyverno.io/v1beta1) evaluator never reads the spec.images and spec.allowedValues fields of a PolicyException. Any PolicyException whose policyRefs and matchConditions match a resource causes image signature verification to be skipped for the entire resource rather than only for the listed images or values, so an exception intended to exempt a single trusted image exempts every image on the matched resource(s). As a result, unsigned or untrusted images can be admitted to the cluster without signature verification. This differs from ValidatingPolicy, GeneratingPolicy, and MutatingPolicy, which treat the same field as a partial exemption. The issue is fixed in version 1.19.1.

Affected products

kyverno: from 1.14.0 before 1.19.1 — fixed in 1.19.1

How to fix

Upgrade to a fixed version: kyverno 1.19.1. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2026-100704 or the next vulnerability affects your stack