How severe is CVE-2026-4342?

CVE-2026-4342 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-4342 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-4342?

CVE-2026-4342 primarily affects Kubernetes Nginx Ingress Controller. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2026-4342?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-4342 have an EU (EUVD) identifier?

Yes. CVE-2026-4342 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13343.

When was CVE-2026-4342 published?

CVE-2026-4342 was published on 2026-03-19 and last updated on 2026-06-17.

CVE-2026-4342

CVE-2026-4342 is a high-severity vulnerability in Kubernetes Nginx Ingress Controller with a CVSS 3.x base score of 8.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: High (CVSS 3.x base score 8.8)
EPSS exploit prediction: 1% (71st percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-13343
Weakness: CWE-20
Affected product: Kubernetes Nginx Ingress Controller
Published: 2026-03-19
Last modified: 2026-06-17

Description

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.)

Frequently asked questions

What is 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.)
How severe is CVE-2026-4342?: CVE-2026-4342 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-4342 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (71st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-4342?: CVE-2026-4342 primarily affects Kubernetes Nginx Ingress Controller. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2026-4342?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-4342 have an EU (EUVD) identifier?: Yes. CVE-2026-4342 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-13343.
When was CVE-2026-4342 published?: CVE-2026-4342 was published on 2026-03-19 and last updated on 2026-06-17.

References

Affected products (2)

cpe:2.3:a:kubernetes:nginx_ingress_controller:*:*:*:*:*:*:*:*
cpe:2.3:a:kubernetes:nginx_ingress_controller:1.15.0:*:*:*:*:*:*:*

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