MEDIUM CVSS 6.5
Published: 2026-02-02

CVE-2026-20406

mediatek nr15 Security Advisory (CVE-2026-20406)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-20406 impacting mediatek nr15. Evaluated with CVSS Base Score of 6.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
In Modem, there is a possible system crash due to an uncaught exception. This could lead to remote denial of service, if a UE has connected to a rogue base station controlled by the attacker, with no additional execution privileges needed. User interaction is not needed for exploitation. Patch ID: MOLY01726634; Issue ID: MSV-5728.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Adjacent (AV:A)
Requires shared subnet / local network access
Attack Complexity
Low (AC:L)
No specialized conditions required
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
None (C:N)
No data confidentiality impact
Integrity
None (I:N)
No system modification impact
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product mediatek / nr15
Affected Versions -
Weakness Enumeration CWE-770

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-2026-20406 impacting mediatek nr15.

⚡ Nuclei Detection Template (YAML) cve-2026-20406.yaml
id: cve-2026-20406

info:
  name: mediatek nr15 - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-20406 affecting mediatek nr15.
    Evaluation: In Modem, there is a possible system crash due to an uncaught exception. This could lead to remote denial of service, if a UE has connected to a rogue...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-20406
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    cvss-score: 6.5
    cve-id: CVE-2026-20406
    cwe-id: CWE-770
  tags: cve,cve-2026-20406,mediatek,nr15,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "nr15"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-20406.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-20406
# Target: mediatek nr15 | CVSS: 6.5 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-20406 (mediatek nr15)...")
    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 mediatek nr15 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-2026-20406.sh
# Recommended Remediation & Patching Commands for CVE-2026-20406
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install nr15 2>/dev/null || \
sudo dnf upgrade nr15 2>/dev/null || \
sudo yum update nr15

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i nr15 2>/dev/null || rpm -qa | grep -i nr15

# 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-2026-20406 in mediatek nr15?

Review vendor-specific security notices and update mediatek nr15 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-2026-20406?

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-2026-20406?

CVE-2026-20406 is classified with a CVSS 3.1 Base Score of 6.5 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.5
MEDIUM SEVERITY
CVE ID CVE-2026-20406
Weakness CWE-770
Vendor mediatek
Product nr15
Published 2026-02-02
Vector CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H