CVE-2026-105223: Improper Certificate Validation in maclof kubernetes-client
Description
CVE-2026-105223 is a critical vulnerability in maclof kubernetes-client versions 0.17.0 up to but not including 0.32.0. The issue arises because TLS certificate verification is disabled in parseKubeconfig() and parseKubeconfigFile() functions when the kubeconfig lacks certificate-authority-data, ignoring the insecure-skip-tls-verify setting. This flaw allows on-path attackers to impersonate the Kubernetes API server, potentially capturing Bearer tokens or Basic credentials and tampering with WebSocket or REST API traffic.
CVSS v4.0
Score 9.1critical
Affected software
maclof
kubernetes-client
pkg:github/maclof/kubernetes-clientRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The maclof kubernetes-client versions 0.17.0 through 0.31.x disable TLS certificate verification in the parseKubeconfig() and parseKubeconfigFile() functions when the kubeconfig file does not contain certificate-authority-data. This behavior ignores the insecure-skip-tls-verify flag, leading to improper certificate validation. As a result, an attacker positioned on the network path can impersonate the Kubernetes API server, intercepting authentication tokens or credentials and manipulating API traffic over WebSocket or REST protocols.
Potential Impact
An attacker capable of intercepting network traffic can impersonate the Kubernetes API server due to disabled TLS certificate validation. This allows the attacker to capture sensitive authentication tokens or credentials and tamper with API communications, potentially leading to unauthorized access or manipulation of Kubernetes resources. The vulnerability is rated critical with a CVSS 4.0 score of 9.1.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is available, avoid using affected versions or ensure kubeconfig files include proper certificate-authority-data to enforce TLS verification. Do not rely on insecure-skip-tls-verify settings as they are ignored in these versions.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-04T13:04:00.479Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ac2f7752cdf04f656959e63
Added to database: 10/05/2026, 01:03:49 UTC
Last enriched: 10/05/2026, 01:18:12 UTC
Last updated: 10/05/2026, 01:18:53 UTC
Views: 13
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