CVE-2026-100704

Kyverno before 1.19.1 ImageValidatingPolicy Exception Bypass

Published Sep 26, 2026 CVSS 4.0 · 8.3 High EPSS < 1% KEV · Not listed

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.

Analysis

Technical impact

Kyverno, a Kubernetes policy engine, contained a flaw in versions 1.14.0 through 1.19.0 where the ImageValidatingPolicy evaluator ignored the spec.images and spec.allowedValues fields of a PolicyException. The exception logic would skip signature verification for the entire resource instead of only the specified images, allowing unsigned or untrusted images to be accepted as legitimate. This circumvents one of the core integrity checks that Kyverno provides, potentially leading to the execution of malicious containers. The weakness is identified as CWE‑863.

Affected Systems

The vulnerability affects Kyverno deployments running any version from 1.14.0 up to and including 1.19.0. The specific component involved is the ImageValidatingPolicy (policies.kyverno.io/v1beta1) evaluator within those releases.

Risk and Exploitability

The vulnerability carries a CVSS score of 8.3, indicating a high severity level. The EPSS score is not available, and the vulnerability is not listed in the CISA KEV catalog, so the current threat landscape exposure is unclear. An attacker would need the capability to create or modify PolicyException resources that match the target Kubernetes resources. Once such an exception is in place, any image deployed to the matched resource bypasses signature verification. The attack vector is inferred to be an authenticated privilege that allows modification of PolicyExceptions within the cluster.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

kyverno

unaffected

Version	Status	Constraints
`1.14.0`	affected	< 1.19.1
`1.19.1`	unaffected	—

No data.

Vendor Product Versions

Kyverno

Version	Status	Scheme	Platform
`[1.14.0,1.19.1)`	affected	semver	—
`1.19.1`	unaffected	semver	—

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Upgrade Kyverno to version 1.19.1 or later, which contains the fix for the exception bypass issue.
Limit the creation and modification of PolicyException resources by tightening RBAC permissions, ensuring only authorized users can modify image validation rules.
Implement an admission webhook that enforces image signature verification regardless of PolicyException settings, providing an additional safeguard against bypass.

Generated by OpenCVE AI on September 26, 2026 at 16:27 UTC.

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact High

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity Low

Privileges Required Low

Scope Changed

Confidentiality Impact None

Integrity Impact High

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploit prediction score: < 1% (0.219% probability within 30 days)

Exploitation poc

Automatable no

Technical Impact partial

References

Link	Providers
https://github.com/kyverno/kyverno/security/advisories/GHSA-5cjf-wwfg-pj4c
https://www.vulncheck.com/advisories/kyverno-before-1.19.1-imagevalidatingpolicy-exception-bypass

History

Sep 28, 2026 3:30 PM Scoring metrics updated View changes

Type	Values Removed	Values Added
Metrics		ssvc `{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Sep 26, 2026 1:30 PM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
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.
Title		Kyverno before 1.19.1 ImageValidatingPolicy Exception Bypass
First Time appeared		Kyverno Kyverno kyverno
Weaknesses		CWE-863
CPEs		cpe:2.3:a:kyverno:kyverno::::::::
Vendors & Products		Kyverno Kyverno kyverno
References		https://github.com/kyverno/kyverno/security/advisories/GHSA-5cjf-wwfg-pj4c https://www.vulncheck.com/advisories/kyverno-before-1.19.1-imagevalidatingpolicy-exception-bypass
Metrics		cvssV3_1 `{'score': 7.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N'}` cvssV4_0 `{'score': 8.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N'}`