Improper input validation in Kubernetes Ingress-Nginx
CVE-2026-4342
A security issue was discovered in ingress-nginx where a combination of Ingress annotations can be used to inject configuration into nginx. This can lead to arbitrary code execution in the context of the ingress-nginx controller, and disclosure of Secrets accessible to the controller. (Note that in the default installation, the controller can access all Secrets cluster-wide.)
Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.006 (49.2th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 49th percentile — 49.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.015 · newest: 0.006 · change: -0.009
Affected products
- Kubernetes Ingress-Nginx — versions 1.15.0, 0
- Kubernetes nginx Ingress Controller — versions 1.15.0
Weakness classification (CWE)
Public proof-of-concept exploits
References
- github.com/kubernetes/kubernetes/issues/137893 (Issue Tracking)
- af854a3a-2127-422b-91ae-364da2661108 (Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2026-4342?
- CVE-2026-4342 is a high-severity vulnerability in Kubernetes Ingress-Nginx, classified under Improper Input Validation. CVSS score: 8.8/10. Published 2026-03-19.
- How severe is CVE-2026-4342?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2026-4342 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.