MEDIUM CVSS 6.6
Published: 2026-02-24

CVE-2026-25603

linksys mr9600_firmware Security Advisory (CVE-2026-25603)
↗ Official NIST NVD Record
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2026-25603 impacting linksys mr9600_firmware. Evaluated with CVSS Base Score of 6.6 (MEDIUM).

Original NVD Description

Source: NIST NVD
Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Linksys MR9600, Linksys MX4200 allows that contents of a USB drive partition can be mounted in an arbitrary location of the file system. This may result in the execution of shell scripts in the context of a root user.This issue affects MR9600: 1.0.4.205530; MX4200: 1.0.13.210200.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Physical (AV:P)
Requires physical access to target hardware
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
None (PR:N)
Unauthenticated execution
User Interaction
Required (UI:R)
User must click or open resource
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 linksys / mr9600_firmware
Affected Versions 1.0.4.205530
Weakness Enumeration CWE-22

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-2026-25603 impacting linksys mr9600_firmware.

⚡ Nuclei Detection Template (YAML) cve-2026-25603.yaml
id: cve-2026-25603

info:
  name: linksys mr9600_firmware - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2026-25603 affecting linksys mr9600_firmware.
    Evaluation: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') vulnerability in Linksys MR9600, Linksys MX4200 allows that c...
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2026-25603
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
    cvss-score: 6.6
    cve-id: CVE-2026-25603
    cwe-id: CWE-22
  tags: cve,cve-2026-25603,linksys,mr9600_firmware,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "mr9600_firmware"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2026-25603.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2026-25603
# Target: linksys mr9600_firmware | CVSS: 6.6 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2026-25603 (linksys mr9600_firmware)...")
    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 linksys mr9600_firmware scope (1.0.4.205530).")
        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-2026-25603.sh
# Recommended Remediation & Patching Commands for CVE-2026-25603
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install mr9600_firmware 2>/dev/null || \
sudo dnf upgrade mr9600_firmware 2>/dev/null || \
sudo yum update mr9600_firmware

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i mr9600_firmware 2>/dev/null || rpm -qa | grep -i mr9600_firmware

# 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-2026-25603 in linksys mr9600_firmware?

Review vendor-specific security notices and update linksys mr9600_firmware 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-2026-25603?

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-2026-25603?

CVE-2026-25603 is classified with a CVSS 3.1 Base Score of 6.6 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
6.6
MEDIUM SEVERITY
CVE ID CVE-2026-25603
Weakness CWE-22
Vendor linksys
Product mr9600_firmware
Published 2026-02-24
Vector CVSS:3.1/AV:P/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H