GHSA-fcfr-fr8g-qjqv: Kyverno before 1.19.2 Cosign Identity Check Bypass via Empty SAN Certificates

Published Nov 5, 2026

Updated

Kyverno before 1.19.2 contains an authentication bypass in matchCertificateData that skips verifyImages subject and subjectRegExp checks when the signing certificate has no Subject Alternative Name. Attackers holding a leaf certificate from a configured private trust root can omit the SAN, set the expected Fulcio issuer OID, and sign malicious images that are admitted despite signer pinning.

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade Kyverno to a version that resolves this vulnerability.
Fixed in 1.19.2

Event History

Nov 5, 2026

CVE Published

via OSV·02:25 AM

Data Sourced

via OSV·02:25 AM

DescriptionSeverityWeakness

Frequently Asked Questions

Which deployments are realistically exposed?

Kyverno deployments before 1.19.2 are exposed where image admission relies on verifyImages certificate identity checks using subject or subjectRegExp and trusts a private root that can issue the relevant leaf certificates.

What does an attacker need to exploit this?

The attacker needs a leaf certificate issued by a configured private trust root. They must create it without a Subject Alternative Name, include the expected Fulcio issuer OID, and use it to sign a malicious image.

What is the practical impact of a successful bypass?

A malicious image can be admitted even when signer identity pinning is configured. The missing SAN causes Kyverno to skip the configured subject and subjectRegExp checks.

What version should be deployed to remediate the issue?

Upgrade Kyverno to version 1.19.2 or later. The affected versions are those before 1.19.2.

GHSA-fcfr-fr8g-qjqv: Kyverno before 1.19.2 Cosign Identity Check Bypass via Empty SAN Certificates

Remediation

Event History

Frequently Asked Questions

Which deployments are realistically exposed?

What does an attacker need to exploit this?

What is the practical impact of a successful bypass?

What version should be deployed to remediate the issue?

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Frequently Asked Questions

Which deployments are realistically exposed?

What does an attacker need to exploit this?

What is the practical impact of a successful bypass?

What version should be deployed to remediate the issue?