HIGH CVSS 7.2
Published: 2026-02-18

CVE-2026-27178

mjdm majordomo Security Advisory (CVE-2026-27178)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-27178 impacting mjdm majordomo. Evaluated with CVSS Base Score of 7.2 (HIGH).

Original NVD Description

Source: NIST NVD
MajorDoMo (aka Major Domestic Module) contains a stored cross-site scripting (XSS) vulnerability through method parameter injection into the shoutbox. The /objects/?method= endpoint allows unauthenticated execution of stored methods with attacker-controlled parameters. Default methods such as ThisComputer.VolumeLevelChanged pass the user-supplied VALUE parameter directly into the say() function, which stores the message raw in the shouts database table without escaping. The shoutbox widget renders stored messages without sanitization in both PHP rendering code and HTML templates. Because the dashboard widget auto-refreshes every 3 seconds, the injected script executes automatically when any administrator loads the dashboard, enabling session hijack through cookie exfiltration.

📊 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
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product mjdm / majordomo
Affected Versions -
Weakness Enumeration CWE-79

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-2026-27178 impacting mjdm majordomo.

⚡ Nuclei Detection Template (YAML) cve-2026-27178.yaml
id: cve-2026-27178

info:
  name: mjdm majordomo - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-27178 affecting mjdm majordomo.
    Evaluation: MajorDoMo (aka Major Domestic Module) contains a stored cross-site scripting (XSS) vulnerability through method parameter injection into the shoutbox....
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-27178
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
    cvss-score: 7.2
    cve-id: CVE-2026-27178
    cwe-id: CWE-79
  tags: cve,cve-2026-27178,mjdm,majordomo,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "majordomo"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-27178.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-27178
# Target: mjdm majordomo | CVSS: 7.2 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-27178 (mjdm majordomo)...")
    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 mjdm majordomo 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-2026-27178.sh
# Recommended Remediation & Patching Commands for CVE-2026-27178
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install majordomo 2>/dev/null || \
sudo dnf upgrade majordomo 2>/dev/null || \
sudo yum update majordomo

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

# 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-2026-27178 in mjdm majordomo?

Review vendor-specific security notices and update mjdm majordomo 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-2026-27178?

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-2026-27178?

CVE-2026-27178 is classified with a CVSS 3.1 Base Score of 7.2 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.2
HIGH SEVERITY
CVE ID CVE-2026-27178
Weakness CWE-79
Vendor mjdm
Product majordomo
Published 2026-02-18
Vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N