MEDIUM CVSS 6.5
Published: 2026-04-29

CVE-2026-7425

amazon freertos-plus-tcp Security Advisory (CVE-2026-7425)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-7425 impacting amazon freertos-plus-tcp. Evaluated with CVSS Base Score of 6.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
Insufficient option length validation in the IPv6 Router Advertisement parser in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network actor to cause a denial of service (device crash) by sending a crafted Router Advertisement with a truncated PREFIX_INFORMATION option that is smaller than the expected structure size. To mitigate this issue, users should upgrade to the fixed version when available.

📊 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 amazon / freertos-plus-tcp
Affected Versions *
Weakness Enumeration CWE-125

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-2026-7425 impacting amazon freertos-plus-tcp.

⚡ Nuclei Detection Template (YAML) cve-2026-7425.yaml
id: cve-2026-7425

info:
  name: amazon freertos-plus-tcp - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-7425 affecting amazon freertos-plus-tcp.
    Evaluation: Insufficient option length validation in the IPv6 Router Advertisement parser in FreeRTOS-Plus-TCP before V4.2.6 and V4.4.1 allows an adjacent network...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-7425
  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-2026-7425
    cwe-id: CWE-125
  tags: cve,cve-2026-7425,amazon,freertos-plus-tcp,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "freertos-plus-tcp"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-7425.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-7425
# Target: amazon freertos-plus-tcp | 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-2026-7425 (amazon freertos-plus-tcp)...")
    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 amazon freertos-plus-tcp 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-2026-7425.sh
# Recommended Remediation & Patching Commands for CVE-2026-7425
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install freertos-plus-tcp 2>/dev/null || \
sudo dnf upgrade freertos-plus-tcp 2>/dev/null || \
sudo yum update freertos-plus-tcp

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

# 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-2026-7425 in amazon freertos-plus-tcp?

Review vendor-specific security notices and update amazon freertos-plus-tcp 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-2026-7425?

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-2026-7425?

CVE-2026-7425 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-2026-7425
Weakness CWE-125
Vendor amazon
Product freertos-plus-tcp
Published 2026-04-29
Vector CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H