Kubernetes up to 1.13.8/1.14.4/1.15.0 ingress-nginx input validation

Summaryinfo

A vulnerability labeled as very critical has been found in Kubernetes up to 1.13.8/1.14.4/1.15.0. Impacted is an unknown function of the component ingress-nginx. Executing a manipulation can lead to input validation. This vulnerability appears as CVE-2026-4342. The attack may be performed from remote. There is no available exploit. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as very critical was found in Kubernetes up to 1.13.8/1.14.4/1.15.0. This vulnerability affects an unknown part of the component ingress-nginx. The manipulation with an unknown input leads to a input validation vulnerability. The CWE definition for the vulnerability is CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.)

The weakness was presented by wooseokdotkim as 137893. The advisory is shared for download at github.com. This vulnerability was named CVE-2026-4342 since 03/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 05/20/2026).

Upgrading to version 1.13.9, 1.14.5 or 1.15.1 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-0801). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

• Open Source Kubernetes

Productinfo

Type

• Virtualization Software

Name

• Kubernetes

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.13.0
• 1.13.1
• 1.13.2
• 1.13.3
• 1.13.4
• 1.13.5
• 1.13.6
• 1.13.7
• 1.13.8
• 1.14
• 1.14.0
• 1.14.1
• 1.14.2
• 1.14.3
• 1.14.4
• 1.15.0

License

• open-source

Website

• Product: https://github.com/kubernetes/kubernetes/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

VulDB is the best source for vulnerability data and more expert information about this specific topic.

Discussion