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.

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 discl…

Vulnerability class: Drupalgeddon 2 (CVE-2018-7600)

EPSS: 0.001 (17.9th percentile) — read the EPSS interpretation.

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.

Affected products

Kubernetes Ingress-nginx — versions 1.15.0, 0
Kubernetes Nginx_ingress_controller — versions 1.15.0

Weakness classification (CWE)

CWE-20 — Improper Input Validation

Public proof-of-concept exploits

stuartMoorhouse/CVE-2026-4342

References

jordan@liggitt.net (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.