HIGH CVSS 8.5
Published: 2026-01-18

CVE-2026-0863

n8n n8n Security Advisory (CVE-2026-0863)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-0863 impacting n8n n8n. Evaluated with CVSS Base Score of 8.5 (HIGH).

Original NVD Description

Source: NIST NVD
Using string formatting and exception handling, an attacker may bypass n8n's python-task-executor sandbox restrictions and run arbitrary unrestricted Python code in the underlying operating system. The vulnerability can be exploited via the Code block by an authenticated user with basic permissions and can lead to a full n8n instance takeover on instances operating under "Internal" execution mode. If the instance is operating under the "External" execution mode (ex. n8n's official Docker image) - arbitrary code execution occurs inside a Sidecar container and not the main node, which significantly reduces the vulnerability impact.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
High (AC:H)
Depends on race conditions or environment
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
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 n8n / n8n
Affected Versions *
Weakness Enumeration CWE-95

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-2026-0863 impacting n8n n8n.

⚡ Nuclei Detection Template (YAML) cve-2026-0863.yaml
id: cve-2026-0863

info:
  name: n8n n8n - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-0863 affecting n8n n8n.
    Evaluation: Using string formatting and exception handling, an attacker may bypass n8n's python-task-executor sandbox restrictions and run arbitrary unrestri...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-0863
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
    cvss-score: 8.5
    cve-id: CVE-2026-0863
    cwe-id: CWE-95
  tags: cve,cve-2026-0863,n8n,n8n,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "n8n"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-0863.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-0863
# Target: n8n n8n | CVSS: 8.5 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-0863 (n8n n8n)...")
    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 n8n n8n 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-2026-0863.sh
# Recommended Remediation & Patching Commands for CVE-2026-0863
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install n8n 2>/dev/null || \
sudo dnf upgrade n8n 2>/dev/null || \
sudo yum update n8n

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i n8n 2>/dev/null || rpm -qa | grep -i n8n

# 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-2026-0863 in n8n n8n?

Review vendor-specific security notices and update n8n n8n 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-2026-0863?

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-2026-0863?

CVE-2026-0863 is classified with a CVSS 3.1 Base Score of 8.5 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
8.5
HIGH SEVERITY
CVE ID CVE-2026-0863
Weakness CWE-95
Vendor n8n
Product n8n
Published 2026-01-18
Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H