PYSEC-2026-3685

Vulnerability from pysec - Published: 2026-08-19 11:56 - Updated: 2026-08-19 12:16
VLAI
Details

MCP Server Kubernetes before 3.9.0 contains an argument injection vulnerability in structured tools (kubectl_get, kubectl_describe, kubectl_delete) that allows attackers to bypass the assertNoDangerousFlags security check by supplying resourceType and name parameters with leading dashes. Attackers can inject the --server flag to redirect kubectl commands to an attacker-controlled API server, causing the operator's bearer token to be transmitted externally and enabling full cluster compromise.

Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3 (Critical)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
Impacted products
Name purl
mcp-server-kubernetes pkg:pypi/mcp-server-kubernetes
Aliases
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "mcp-server-kubernetes",
        "purl": "pkg:pypi/mcp-server-kubernetes"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.9.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.1.0",
        "0.1.1",
        "0.1.2",
        "0.1.3",
        "0.1.6"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-61459",
    "GHSA-wmg3-h8mf-wgvr"
  ],
  "details": "MCP Server Kubernetes before 3.9.0 contains an argument injection vulnerability in structured tools (kubectl_get, kubectl_describe, kubectl_delete) that allows attackers to bypass the assertNoDangerousFlags security check by supplying resourceType and name parameters with leading dashes. Attackers can inject the --server flag to redirect kubectl commands to an attacker-controlled API server, causing the operator\u0027s bearer token to be transmitted externally and enabling full cluster compromise.",
  "id": "PYSEC-2026-3685",
  "modified": "2026-08-19T12:16:28.926024Z",
  "published": "2026-08-19T11:56:25.076274Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-61459"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Flux159/mcp-server-kubernetes/issues/328"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Flux159/mcp-server-kubernetes/pull/329"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Flux159/mcp-server-kubernetes/commit/d7890f50a4567bf5d9842541ba6f41e180227f9a"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/Flux159/mcp-server-kubernetes"
    },
    {
      "type": "WEB",
      "url": "https://github.com/Flux159/mcp-server-kubernetes/releases/tag/3.9.0"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/mcp-server-kubernetes-argument-injection-via-kubectl-structured-tools"
    },
    {
      "type": "PACKAGE",
      "url": "https://pypi.org/project/mcp-server-kubernetes"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-wmg3-h8mf-wgvr"
    }
  ],
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "mcp-server-kubernetes argument injection can expose Kubernetes cluster credentials"
}



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