Vulnerability in Kyverno
CVE-2026-122318
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.
Vulnerability class: Improper Certificate Validation
Published · last modified .
CVSS v3 metric
CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:L/I:H/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/kyverno/kyverno/security/advisories/GHSA-fcfr-fr8g-qjqv (vendor-advisory)
- www.vulncheck.com/advisories/kyverno-before-1.19.2-cosign-identity-check-bypass… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-122318?
- CVE-2026-122318 is a high-severity vulnerability in Kyverno, classified under Improper Certificate Validation. CVSS score: 7.7/10. Published 2026-11-05.
- How severe is CVE-2026-122318?
- High severity. CVSS v3 base score is 7.7 out of 10.