MEDIUM CVSS 4.8
Published: 2026-04-08

CVE-2026-39391

ci4-cms-erp ci4ms Security Advisory (CVE-2026-39391)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-39391 impacting ci4-cms-erp ci4ms. Evaluated with CVSS Base Score of 4.8 (MEDIUM).

Original NVD Description

Source: NIST NVD
CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to 0.31.4.0, the blacklist (ban) note parameter in UserController::ajax_blackList_post() is stored in the database without sanitization and rendered into an HTML data-note attribute without escaping. An admin with blacklist privileges can inject arbitrary JavaScript that executes in the browser of any other admin who views the user management page. This vulnerability is fixed in 0.31.4.0.

📊 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
High (PR:H)
Administrative credentials required
User Interaction
Required (UI:R)
User must click or open resource
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 ci4-cms-erp / ci4ms
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-2026-39391 impacting ci4-cms-erp ci4ms.

⚡ Nuclei Detection Template (YAML) cve-2026-39391.yaml
id: cve-2026-39391

info:
  name: ci4-cms-erp ci4ms - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-39391 affecting ci4-cms-erp ci4ms.
    Evaluation: CI4MS is a CodeIgniter 4-based CMS skeleton that delivers a production-ready, modular architecture with RBAC authorization and theme support. Prior to...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-39391
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 4.8
    cve-id: CVE-2026-39391
    cwe-id: CWE-79
  tags: cve,cve-2026-39391,ci4-cms-erp,ci4ms,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "ci4ms"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-39391.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-39391
# Target: ci4-cms-erp ci4ms | CVSS: 4.8 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-39391 (ci4-cms-erp ci4ms)...")
    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 ci4-cms-erp ci4ms 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-2026-39391.sh
# Recommended Remediation & Patching Commands for CVE-2026-39391
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install ci4ms 2>/dev/null || \
sudo dnf upgrade ci4ms 2>/dev/null || \
sudo yum update ci4ms

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i ci4ms 2>/dev/null || rpm -qa | grep -i ci4ms

# 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

Authorities
  • No records filed in this category.
Distributions
  • No records filed in this category.

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-39391 in ci4-cms-erp ci4ms?

Review vendor-specific security notices and update ci4-cms-erp ci4ms 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-2026-39391?

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-2026-39391?

CVE-2026-39391 is classified with a CVSS 3.1 Base Score of 4.8 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
4.8
MEDIUM SEVERITY
CVE ID CVE-2026-39391
Weakness CWE-79
Vendor ci4-cms-erp
Product ci4ms
Published 2026-04-08
Vector CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N