MEDIUM CVSS 6.5
Published: 2026-03-25

CVE-2026-27496

n8n n8n Security Advisory (CVE-2026-27496)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-27496 impacting n8n n8n. Evaluated with CVSS Base Score of 6.5 (MEDIUM).

Original NVD Description

Source: NIST NVD
n8n is an open source workflow automation platform. Prior to versions 1.123.22, 2.9.3, and 2.10.1, an authenticated user with permission to create or modify workflows could use the JavaScript Task Runner to allocate uninitialized memory buffers. Uninitialized buffers may contain residual data from the same Node.js process — including data from prior requests, tasks, secrets, or tokens — resulting in information disclosure of sensitive in-process data. Task Runners must be enabled using `N8N_RUNNERS_ENABLED=true`. In external runner mode, the impact is limited to data within the external runner process. The issue has been fixed in n8n versions 1.123.22, 2.10.1 , and 2.9.3. Users should upgrade to this version or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations: Limit workflow creation and editing permissions to fully trusted users only, and/or use external runner mode (`N8N_RUNNERS_MODE=external`) to isolate the runner process. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

📊 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
None (I:N)
No system modification impact
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product n8n / n8n
Affected Versions *
Weakness Enumeration CWE-908

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-2026-27496 impacting n8n n8n.

⚡ Nuclei Detection Template (YAML) cve-2026-27496.yaml
id: cve-2026-27496

info:
  name: n8n n8n - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-27496 affecting n8n n8n.
    Evaluation: n8n is an open source workflow automation platform. Prior to versions 1.123.22, 2.9.3, and 2.10.1, an authenticated user with permission to create or ...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-27496
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
    cvss-score: 6.5
    cve-id: CVE-2026-27496
    cwe-id: CWE-908
  tags: cve,cve-2026-27496,n8n,n8n,medium

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-2026-27496.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-27496
# Target: n8n n8n | 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-2026-27496 (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-2026-27496.sh
# Recommended Remediation & Patching Commands for CVE-2026-27496
# 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.

🔗 Verified Technical References

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-27496 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-2026-27496?

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-2026-27496?

CVE-2026-27496 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-2026-27496
Weakness CWE-908
Vendor n8n
Product n8n
Published 2026-03-25
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N