CVE-2025-9708: KubernetesClient Kubernetes C# Client Accepts Certificates Vulnerability

MODERATE
Advisory Identifier: GHSA-w7r3-mgwf-4mqq
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CVSS 6.8
CWE-295
Published
Advisory Summary

CVE-2025-9708 is a MODERATE (CVSS 6.8) kubernetes c# client accepts certificates vulnerability (CWE-295: Improper Certificate Validation) affecting KubernetesClient libraries in the NuGet ecosystem. The issue involves kubernetes c# client accepts certificates from any ca without properly verifying the trust chain. Remediation is available by upgrading affected packages to version 17.0.14.

CVE-2025-9708 at a Glance

CVE Identifier CVE-2025-9708
GHSA Identifier GHSA-w7r3-mgwf-4mqq
Severity MODERATE
CVSS v3.1 Base Score 6.8
CWE Classification CWE-295: Improper Certificate Validation
Affected Product KubernetesClient
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 6.8

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability None (A:N)

How to Fix CVE-2025-9708

To remediate this vulnerability, upgrade all affected KubernetesClient dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

KubernetesClient fixed: 17.0.14 
Upgrade KubernetesClient to 17.0.14
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for KubernetesClient

How to Check if You Are Affected

To determine whether your application is affected by CVE-2025-9708, inspect your project dependencies for KubernetesClient:

inspect dependencies for KubernetesClient

Analyze the terminal output to locate any version of KubernetesClient in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 17.0.14), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-295: Improper Certificate Validation, where the product does not validate, or incorrectly validates, a certificate. In KubernetesClient, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A vulnerability exists in the Kubernetes C# client where the certificate validation logic accepts properly constructed certificates from any Certificate Authority (CA) without properly verifying the trust chain. This flaw allows a malicious actor to present a forged certificate and potentially intercept or manipulate communication with the Kubernetes API server, leading to possible man-in-the-middle attacks and API impersonation.

CVE-2025-9708 Affected KubernetesClient Versions

1 component(s)
Fixed Versions:
17.0.14
Product / Package Ecosystem Affected Versions Fixed Version
KubernetesClient
nuget/KubernetesClient
NuGet
< 17.0.14
17.0.14

References

NVD — CVE-2025-9708 NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-9708
KubernetesClient Source Repository REPOSITORY
https://github.com/kubernetes/kubernetes/issues/134063
KubernetesClient Source Repository REPOSITORY
https://github.com/kubernetes-client/csharp
KubernetesClient Security Information SECURITY
https://groups.google.com/g/kubernetes-security-announce/c/rLopt2Msvbw/m/rK6XeNw2CgAJ
KubernetesClient Security Information SECURITY
http://www.openwall.com/lists/oss-security/2025/09/16/1

Frequently Asked Questions

What is CVE-2025-9708?
CVE-2025-9708 is a security vulnerability in KubernetesClient involving Kubernetes C# client accepts certificates from any CA without properly verifying the trust chain under CWE-295: Improper Certificate Validation.
Which KubernetesClient versions are affected?
Affected versions include releases prior to 17.0.14 across affected packages: KubernetesClient.
What version fixes CVE-2025-9708?
Upgrading to 17.0.14 (or the latest patched release for your respective branch) resolves the vulnerability.
Is KubernetesClient affected?
Yes, KubernetesClient is affected in releases prior to 17.0.14. Upgrade your dependency to 17.0.14 or later.
What is the CVSS score of CVE-2025-9708?
CVE-2025-9708 has a CVSS v3.1 base score of 6.8 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N.
What CWE is associated with CVE-2025-9708?
CVE-2025-9708 is classified under CWE-295: Improper Certificate Validation (The product does not validate, or incorrectly validates, a certificate.).
How can I check NuGet dependencies for CVE-2025-9708?
Run the dependency tree command: 'inspect dependencies for KubernetesClient'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-w7r3-mgwf-4mqq",
  "modified" : "2025-11-05T20:44:42Z",
  "published" : "2025-09-17T00:31:11Z",
  "aliases" : [ "CVE-2025-9708" ],
  "summary" : "Kubernetes C# client accepts certificates from any CA without properly verifying the trust chain",
  "details" : "A vulnerability exists in the Kubernetes C# client where the certificate validation logic accepts properly constructed certificates from any Certificate Authority (CA) without properly verifying the trust chain. This flaw allows a malicious actor to present a forged certificate and potentially intercept or manipulate communication with the Kubernetes API server, leading to possible man-in-the-middle attacks and API impersonation.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "KubernetesClient"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "17.0.14"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2025-9708"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/kubernetes/kubernetes/issues/134063"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/kubernetes-client/csharp"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/g/kubernetes-security-announce/c/rLopt2Msvbw/m/rK6XeNw2CgAJ"
  }, {
    "type" : "WEB",
    "url" : "http://www.openwall.com/lists/oss-security/2025/09/16/1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-295" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2025-09-17T19:07:53Z",
    "nvd_published_at" : "2025-09-16T22:15:33Z"
  }
}