MEDIUM CVSS 5.6
Published: 2026-03-27

CVE-2026-4621

nec aterm_wg1200hp4_firmware Security Advisory (CVE-2026-4621)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-4621 impacting nec aterm_wg1200hp4_firmware. Evaluated with CVSS Base Score of 5.6 (MEDIUM).

Original NVD Description

Source: NIST NVD
Hidden Functionality vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to enable telnet via network.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Unchanged (S:U)
Confined to same security context
Confidentiality
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
Low (A:L)
Partial service performance degradation

🎯 Affected Versions Matrix

Affected Product nec / aterm_wg1200hp4_firmware
Affected Versions *
Weakness Enumeration CWE-912

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-2026-4621 impacting nec aterm_wg1200hp4_firmware.

⚡ Nuclei Detection Template (YAML) cve-2026-4621.yaml
id: cve-2026-4621

info:
  name: nec aterm_wg1200hp4_firmware - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-4621 affecting nec aterm_wg1200hp4_firmware.
    Evaluation: Hidden Functionality vulnerability in NEC Platforms, Ltd. Aterm Series allows a attacker to enable telnet via network....
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-4621
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
    cvss-score: 5.6
    cve-id: CVE-2026-4621
    cwe-id: CWE-912
  tags: cve,cve-2026-4621,nec,aterm_wg1200hp4_firmware,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "aterm_wg1200hp4_firmware"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-4621.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-4621
# Target: nec aterm_wg1200hp4_firmware | CVSS: 5.6 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-4621 (nec aterm_wg1200hp4_firmware)...")
    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 nec aterm_wg1200hp4_firmware 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-2026-4621.sh
# Recommended Remediation & Patching Commands for CVE-2026-4621
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install aterm_wg1200hp4_firmware 2>/dev/null || \
sudo dnf upgrade aterm_wg1200hp4_firmware 2>/dev/null || \
sudo yum update aterm_wg1200hp4_firmware

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i aterm_wg1200hp4_firmware 2>/dev/null || rpm -qa | grep -i aterm_wg1200hp4_firmware

# 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.

🔗 Verified Technical References

Authorities
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Distributions
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❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-4621 in nec aterm_wg1200hp4_firmware?

Review vendor-specific security notices and update nec aterm_wg1200hp4_firmware 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-2026-4621?

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-2026-4621?

CVE-2026-4621 is classified with a CVSS 3.1 Base Score of 5.6 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.6
MEDIUM SEVERITY
CVE ID CVE-2026-4621
Weakness CWE-912
Vendor nec
Product aterm_wg1200hp4_firmware
Published 2026-03-27
Vector CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L