HIGH CVSS 7.8
Published: 2026-02-10

CVE-2026-25656

siemens sinec_nms Security Advisory (CVE-2026-25656)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-25656 impacting siemens sinec_nms. Evaluated with CVSS Base Score of 7.8 (HIGH).

Original NVD Description

Source: NIST NVD
A vulnerability has been identified in SINEC NMS (All versions < V4.0 SP3), User Management Component (UMC) (All versions < V2.15.2.1). The affected application permits improper modification of a configuration file by a low-privileged user. This could allow an attacker to load malicious DLLs, potentially leading to arbitrary code execution with SYSTEM privileges.(ZDI-CAN-28108)

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Local (AV:L)
Requires local system execution permissions
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
High (I:H)
Total modification of target system
Availability
High (A:H)
Total denial of service or shutdown

🎯 Affected Versions Matrix

Affected Product siemens / sinec_nms
Affected Versions -
Weakness Enumeration CWE-427

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-2026-25656 impacting siemens sinec_nms.

⚡ Nuclei Detection Template (YAML) cve-2026-25656.yaml
id: cve-2026-25656

info:
  name: siemens sinec_nms - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: high
  description: |
    Automated signature & scanner for CVE-2026-25656 affecting siemens sinec_nms.
    Evaluation: A vulnerability has been identified in SINEC NMS (All versions &lt; V4.0 SP3), User Management Component (UMC) (All versions &lt; V2.15.2.1). The affe...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-25656
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    cvss-score: 7.8
    cve-id: CVE-2026-25656
    cwe-id: CWE-427
  tags: cve,cve-2026-25656,siemens,sinec_nms,high

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "sinec_nms"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-25656.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-25656
# Target: siemens sinec_nms | CVSS: 7.8 (HIGH)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-25656 (siemens sinec_nms)...")
    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 siemens sinec_nms 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-2026-25656.sh
# Recommended Remediation & Patching Commands for CVE-2026-25656
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install sinec_nms 2>/dev/null || \
sudo dnf upgrade sinec_nms 2>/dev/null || \
sudo yum update sinec_nms

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

# 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
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Distributions
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❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2026-25656 in siemens sinec_nms?

Review vendor-specific security notices and update siemens sinec_nms 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-2026-25656?

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-2026-25656?

CVE-2026-25656 is classified with a CVSS 3.1 Base Score of 7.8 (HIGH). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
7.8
HIGH SEVERITY
CVE ID CVE-2026-25656
Weakness CWE-427
Vendor siemens
Product sinec_nms
Published 2026-02-10
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H