Auth bypass in Kyverno
CVE-2026-100704
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.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N.
EPSS exploit prediction
EPSS: 0.002 (12.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 12.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.000
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-5cjf-wwfg-pj4c) (vendor-advisory)
- VulnCheck Advisory: Kyverno before 1.19.1 ImageValidatingPolicy Exception Bypass (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100704?
- CVE-2026-100704 is a high-severity vulnerability in Kyverno, classified under Incorrect Authorization. CVSS score: 7.7/10. Published 2026-09-26.
- How severe is CVE-2026-100704?
- High severity. CVSS v3 base score is 7.7 out of 10.