CRITICAL CVSS 10.0
Published: 2026-06-23

CVE-2026-48020

traefik traefik Security Advisory (CVE-2026-48020)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-48020 impacting traefik traefik. Evaluated with CVSS Base Score of 10.0 (CRITICAL).

Original NVD Description

Source: NIST NVD
Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's StripPrefix middleware that allows an unauthenticated attacker to bypass route-level authentication and authorization. When a public router matches on a PathPrefix rule and applies the StripPrefix middleware, a request path containing .. or its percent-encoded form %2e%2e can match the public route at routing time and then, after the prefix is stripped and the path is normalized, resolve to a path served by a separate, authenticated router. As a result, an attacker can reach protected backend paths — such as admin or internal configuration endpoints — without satisfying the authentication middleware attached to the protected router. This vulnerability is fixed in 2.11.48, 3.6.19, and 3.7.3.

📊 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
None (PR:N)
Unauthenticated execution
User Interaction
None (UI:N)
Zero human interaction required
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
High (C:H)
Total information disclosure
Integrity
High (I:H)
Total modification of target system
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product traefik / traefik
Affected Versions *
Weakness Enumeration CWE-288

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-2026-48020 impacting traefik traefik.

⚡ Nuclei Detection Template (YAML) cve-2026-48020.yaml
id: cve-2026-48020

info:
  name: traefik traefik - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: critical
  description: |
    Automated signature & scanner for CVE-2026-48020 affecting traefik traefik.
    Evaluation: Traefik is an HTTP reverse proxy and load balancer. Prior to 2.11.48, 3.6.19, and 3.7.3, there is a high severity vulnerability in Traefik's Stri...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-48020
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
    cvss-score: 10.0
    cve-id: CVE-2026-48020
    cwe-id: CWE-288
  tags: cve,cve-2026-48020,traefik,traefik,critical

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "traefik"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-48020.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-48020
# Target: traefik traefik | CVSS: 10.0 (CRITICAL)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-48020 (traefik traefik)...")
    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 traefik traefik 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-2026-48020.sh
# Recommended Remediation & Patching Commands for CVE-2026-48020
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install traefik 2>/dev/null || \
sudo dnf upgrade traefik 2>/dev/null || \
sudo yum update traefik

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

# 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-2026-48020 in traefik traefik?

Review vendor-specific security notices and update traefik traefik 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-2026-48020?

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-2026-48020?

CVE-2026-48020 is classified with a CVSS 3.1 Base Score of 10.0 (CRITICAL). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
10.0
CRITICAL SEVERITY
CVE ID CVE-2026-48020
Weakness CWE-288
Vendor traefik
Product traefik
Published 2026-06-23
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N