HIGH CVSS 7.7
Published: 2026-03-07

CVE-2026-29186

linuxfoundation backstage_plugin-techdocs-node Security Advisory (CVE-2026-29186)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-29186 impacting linuxfoundation backstage_plugin-techdocs-node. Evaluated with CVSS Base Score of 7.7 (HIGH).

Original NVD Description

Source: NIST NVD
Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbitrary code execution. The @backstage/plugin-techdocs-node package uses an allowlist to filter dangerous MkDocs configuration keys during the documentation build process. A gap in this allowlist allows attackers to craft an mkdocs.yml that causes arbitrary Python code execution, completely bypassing TechDocs' security controls. This issue has been patched in version 1.14.3.

📊 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
Low (I:L)
Partial data modification possible
Availability
Low (A:L)
Partial service performance degradation

🎯 Affected Versions Matrix

Affected Product linuxfoundation / backstage_plugin-techdocs-node
Affected Versions *
Weakness Enumeration CWE-74

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-2026-29186 impacting linuxfoundation backstage_plugin-techdocs-node.

⚡ Nuclei Detection Template (YAML) cve-2026-29186.yaml
id: cve-2026-29186

info:
  name: linuxfoundation backstage_plugin-techdocs-node - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-29186 affecting linuxfoundation backstage_plugin-techdocs-node.
    Evaluation: Backstage is an open framework for building developer portals. Prior to version 1.14.3, this is a configuration bypass vulnerability that enables arbi...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-29186
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L
    cvss-score: 7.7
    cve-id: CVE-2026-29186
    cwe-id: CWE-74
  tags: cve,cve-2026-29186,linuxfoundation,backstage_plugin-techdocs,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "backstage_plugin-techdocs-node"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-29186.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-29186
# Target: linuxfoundation backstage_plugin-techdocs-node | CVSS: 7.7 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-29186 (linuxfoundation backstage_plugin-techdocs-node)...")
    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 linuxfoundation backstage_plugin-techdocs-node 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-2026-29186.sh
# Recommended Remediation & Patching Commands for CVE-2026-29186
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install backstage_plugin-techdocs 2>/dev/null || \
sudo dnf upgrade backstage_plugin-techdocs 2>/dev/null || \
sudo yum update backstage_plugin-techdocs

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

# 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-2026-29186 in linuxfoundation backstage_plugin-techdocs-node?

Review vendor-specific security notices and update linuxfoundation backstage_plugin-techdocs-node 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-2026-29186?

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-2026-29186?

CVE-2026-29186 is classified with a CVSS 3.1 Base Score of 7.7 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.7
HIGH SEVERITY
CVE ID CVE-2026-29186
Weakness CWE-74
Vendor linuxfoundation
Product backstage_plugin-techdocs-node
Published 2026-03-07
Vector CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:L/A:L