HIGH CVSS 7.4
Published: 2026-07-10

CVE-2026-53450

coturn_project coturn Security Advisory (CVE-2026-53450)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-53450 impacting coturn_project coturn. Evaluated with CVSS Base Score of 7.4 (HIGH).

Original NVD Description

Source: NIST NVD
Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.0, coturn rejects loopback peers by default unless allow-loopback-peers is enabled, but the default loopback guard can be bypassed by using the IPv4-mapped IPv6 peer address ::ffff:127.0.0.1 in a TURN XOR-PEER-ADDRESS attribute. ioa_addr_is_loopback checks for the literal IPv6 loopback shape before IPv4-mapped IPv6 handling, so good_peer_addr does not apply the default loopback rejection and an authenticated TURN client can expose services bound only to localhost on the coturn host through TURN relay traffic. This issue is fixed in version 4.13.0.

📊 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
Changed (S:C)
Impacts components beyond caller authority
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 coturn_project / coturn
Affected Versions *
Weakness Enumeration CWE-918

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-2026-53450 impacting coturn_project coturn.

⚡ Nuclei Detection Template (YAML) cve-2026-53450.yaml
id: cve-2026-53450

info:
  name: coturn_project coturn - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-53450 affecting coturn_project coturn.
    Evaluation: Coturn is a free open source implementation of TURN and STUN Server. Prior to 4.13.0, coturn rejects loopback peers by default unless allow-loopback-p...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-53450
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L
    cvss-score: 7.4
    cve-id: CVE-2026-53450
    cwe-id: CWE-918
  tags: cve,cve-2026-53450,coturn_project,coturn,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "coturn"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-53450.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-53450
# Target: coturn_project coturn | CVSS: 7.4 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-53450 (coturn_project coturn)...")
    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 coturn_project coturn 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-2026-53450.sh
# Recommended Remediation & Patching Commands for CVE-2026-53450
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install coturn 2>/dev/null || \
sudo dnf upgrade coturn 2>/dev/null || \
sudo yum update coturn

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

# 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-2026-53450 in coturn_project coturn?

Review vendor-specific security notices and update coturn_project coturn 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-2026-53450?

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-2026-53450?

CVE-2026-53450 is classified with a CVSS 3.1 Base Score of 7.4 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.4
HIGH SEVERITY
CVE ID CVE-2026-53450
Weakness CWE-918
Vendor coturn_project
Product coturn
Published 2026-07-10
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:L