HIGH CVSS 8.3
Published: 2026-04-15

CVE-2026-39884

suyogs mcp-server-kubernetes Security Advisory (CVE-2026-39884)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-39884 impacting suyogs mcp-server-kubernetes. Evaluated with CVSS Base Score of 8.3 (HIGH).

Original NVD Description

Source: NIST NVD
mcp-server-kubernetes is a Model Context Protocol server for Kubernetes cluster management. Versions 3.4.0 and prior contain an argument injection vulnerability in the port_forward tool in src/tools/port_forward.ts, where a kubectl command is constructed via string concatenation with user-controlled input and then naively split on spaces before being passed to spawn(). Unlike all other tools in the codebase which correctly use array-based argument passing with execFileSync(), port_forward treats every space in user-controlled fields (namespace, resourceType, resourceName, localPort, targetPort) as an argument boundary, allowing an attacker to inject arbitrary kubectl flags. This enables exposure of internal Kubernetes services to the network by injecting --address=0.0.0.0, cross-namespace targeting by injecting additional -n flags, and indirect exploitation via prompt injection against AI agents connected to the MCP server. This issue has been fixed in version 3.5.0.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
Low (PR:L)
Standard user access required
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
Low (A:L)
Partial service performance degradation

🎯 Affected Versions Matrix

Affected Product suyogs / mcp-server-kubernetes
Affected Versions *
Weakness Enumeration CWE-88

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2026-39884 impacting suyogs mcp-server-kubernetes.

⚡ Nuclei Detection Template (YAML) cve-2026-39884.yaml
id: cve-2026-39884

info:
  name: suyogs mcp-server-kubernetes - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-39884 affecting suyogs mcp-server-kubernetes.
    Evaluation: mcp-server-kubernetes is a Model Context Protocol server for Kubernetes cluster management. Versions 3.4.0 and prior contain an argument injection vul...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-39884
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
    cvss-score: 8.3
    cve-id: CVE-2026-39884
    cwe-id: CWE-88
  tags: cve,cve-2026-39884,suyogs,mcp-server-kubernetes,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "mcp-server-kubernetes"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-39884.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-39884
# Target: suyogs mcp-server-kubernetes | CVSS: 8.3 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-39884 (suyogs mcp-server-kubernetes)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against suyogs mcp-server-kubernetes scope (*).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2026-39884.sh
# Recommended Remediation & Patching Commands for CVE-2026-39884
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install mcp-server-kubernetes 2>/dev/null || \
sudo dnf upgrade mcp-server-kubernetes 2>/dev/null || \
sudo yum update mcp-server-kubernetes

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i mcp-server-kubernetes 2>/dev/null || rpm -qa | grep -i mcp-server-kubernetes

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-39884 in suyogs mcp-server-kubernetes?

Review vendor-specific security notices and update suyogs mcp-server-kubernetes packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2026-39884?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2026-39884?

CVE-2026-39884 is classified with a CVSS 3.1 Base Score of 8.3 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.3
HIGH SEVERITY
CVE ID CVE-2026-39884
Weakness CWE-88
Vendor suyogs
Product mcp-server-kubernetes
Published 2026-04-15
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L