What is CVE-2026-122306?

CVE-2026-122306 is a high-severity vulnerability in Kyverno, classified under Inefficient Algorithmic Complexity. CVSS score: 7.7/10. Published 2026-11-05.

How severe is CVE-2026-122306?

High severity. CVSS v3 base score is 7.7 out of 10.

Vulnerability in Kyverno

CVE-2026-122306

Kyverno before 1.19.2 contains a denial of service vulnerability that allows namespaced policy authors to exhaust admission controller CPU by submitting pathological wildcard patterns. Attackers can create a Policy with crafted match and exclude names evaluated by ValidateMatchExcludeConflict, pinning cores and causing cluster-wide webhook timeouts that block resource operations.

Published 2026-11-05 · last modified 2026-11-05.

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:N/A:H.

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

Kyverno

Weakness classification (CWE)

CWE-407 — Inefficient Algorithmic Complexity

References

GitHub Security Advisory (GHSA-8mrj-27wr-599g) (vendor-advisory)
VulnCheck Advisory: Kyverno before 1.19.2 Denial of Service via Exponential-Time Wildcard Matching (third-party-advisory)

Frequently asked questions

What is CVE-2026-122306?: CVE-2026-122306 is a high-severity vulnerability in Kyverno, classified under Inefficient Algorithmic Complexity. CVSS score: 7.7/10. Published 2026-11-05.
How severe is CVE-2026-122306?: High severity. CVSS v3 base score is 7.7 out of 10.