HIGH CVSS 8.8
Published: 2026-01-19

CVE-2026-1143

totolink a3700r_firmware Security Advisory (CVE-2026-1143)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2026-1143?
🔬 Search Writeups & Exploit Archive →

CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-1143 impacting totolink a3700r_firmware. Evaluated with CVSS Base Score of 8.8 (HIGH).

Original NVD Description

Source: NIST NVD
A weakness has been identified in TOTOLINK A3700R 9.1.2u.5822_B20200513. This affects the function setWiFiEasyGuestCfg of the file /cgi-bin/cstecgi.cgi. Executing a manipulation of the argument ssid can lead to buffer overflow. The attack may be launched remotely. The exploit has been made available to the public and could be used for attacks.

📊 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
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product totolink / a3700r_firmware
Affected Versions 9.1.2u.5822_b20200513
Weakness Enumeration CWE-119

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-2026-1143 impacting totolink a3700r_firmware.

⚡ Nuclei Detection Template (YAML) cve-2026-1143.yaml
id: cve-2026-1143

info:
  name: totolink a3700r_firmware - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-1143 affecting totolink a3700r_firmware.
    Evaluation: A weakness has been identified in TOTOLINK A3700R 9.1.2u.5822_B20200513. This affects the function setWiFiEasyGuestCfg of the file /cgi-bin/cstecgi.cg...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-1143
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 8.8
    cve-id: CVE-2026-1143
    cwe-id: CWE-119
  tags: cve,cve-2026-1143,totolink,a3700r_firmware,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "a3700r_firmware"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-1143.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-1143
# Target: totolink a3700r_firmware | CVSS: 8.8 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-1143 (totolink a3700r_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 totolink a3700r_firmware scope (9.1.2u.5822_b20200513).")
        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-2026-1143.sh
# Recommended Remediation & Patching Commands for CVE-2026-1143
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install a3700r_firmware 2>/dev/null || \
sudo dnf upgrade a3700r_firmware 2>/dev/null || \
sudo yum update a3700r_firmware

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i a3700r_firmware 2>/dev/null || rpm -qa | grep -i a3700r_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.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-1143 in totolink a3700r_firmware?

Review vendor-specific security notices and update totolink a3700r_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-2026-1143?

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-2026-1143?

CVE-2026-1143 is classified with a CVSS 3.1 Base Score of 8.8 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.8
HIGH SEVERITY
CVE ID CVE-2026-1143
Weakness CWE-119
Vendor totolink
Product a3700r_firmware
Published 2026-01-19
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H