# CVE-2026-122318: Kyverno before 1.19.2 Cosign Identity Check Bypass via Empty SAN Certificates

Status: published. Published: 2026-11-05. Updated: 2026-11-05.

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

No remediation reported in collected sources

## Affected products and versions

- kyverno / kyverno (github.com/kyverno/kyverno): ≥ 0; < 1.19.2 (affected, semver); 1.19.2 (unaffected, semver). Source: CNA: VulnCheck

## Severity and prioritization

- CVSS 4.0: 7.2 (high); CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:N/VC:L/VI:H/VA:L/SC:L/SI:H/SA:L; source: CNA: VulnCheck

- CVSS 3.1: 7.7 (high); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:L; source: CNA: VulnCheck

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-295

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/kyverno/kyverno/security/advisories/GHSA-fcfr-fr8g-qjqv (CNA: VulnCheck; vendor-advisory)

- https://www.vulncheck.com/advisories/kyverno-before-1.19.2-cosign-identity-check-bypass-via-empty-san-certificates (CNA: VulnCheck; third-party-advisory)

## Provenance

- CNA: VulnCheck: https://www.cve.org/CVERecord?id=CVE-2026-122318; retrieved 2026-11-05; source updated 2026-11-05

Revision: a71a7c489cddb13be0d80c5e38d2e8f1a0a5d33bc63a1a6953eb87e842124803

Canonical: https://y2.dev/cve/CVE-2026-122318

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