CVE-2026-102406 — Authorization Bypass Through User-Controlled Key (CWE-639) in Kibana could lead to…¶

Key facts

CVE-2026-102406 is a High (8.8) vulnerability: Authorization Bypass Through User-Controlled Key (CWE-639) in Kibana could lead to…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-102406
Severity	High (8.8)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-102406/

Details¶

English | 한국어

Description¶

Authorization Bypass Through User-Controlled Key (CWE-639) in Kibana could lead to cross-tenant data interception. In this context, "tenant" refers to a user or team sharing the same Kibana deployment, not a separate Elastic Cloud organization or customer. Kibana's Fleet package installation process allowed a user holding delegated Fleet package-management privileges, without direct Elasticsearch administrative privileges, to claim a data stream identifier already in use by another tenant. Because ownership of that identifier was not verified before Fleet applied the uploaded package's generated index and ingest-pipeline settings to already-existing infrastructure, an attacker could redirect an existing tenant's data stream through infrastructure under their control. This exposed the affected tenant's subsequently ingested data to unauthorized disclosure and modification, and prevented that data from reaching its intended destination. Interception could continue even after the malicious package was removed, requiring separate remediation of the affected infrastructure.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-102406
Type	RCE
CVSS Score	8.8

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-102406/poc.py

Usage¶

# Run PoC against target
python3 poc.py --target <TARGET_URL>

# With authentication
python3 poc.py --target <TARGET_URL> --username <USER> --password <PASS>

⚠️ Warning: This PoC is for authorized security testing only. It uses detection-only techniques and does not exploit or damage target systems.

Test Lab¶

This repository includes a Docker-based test environment with both vulnerable and patched applications.

Quick Start¶

# Clone and navigate to CVE directory
cd CVE-2026-102406

# Start both applications
docker-compose up -d

# Run tests
./run-tests.sh    # Linux/Mac
./run-tests.ps1   # Windows PowerShell

Application Endpoints¶

Application	URL	Status
Vulnerable App	http://localhost:8080	Shows vulnerability
Patched App	http://localhost:8081	Demonstrates fix

Directory Structure¶

├── README.md           # English documentation
├── README_KO.md        # Korean documentation
├── poc.py              # PoC detection script
├── docker-compose.yml  # Container orchestration
├── run-tests.sh        # Linux/Mac test runner
├── run-tests.ps1       # Windows test runner
├── vulnerable-app/     # Vulnerable version
│   ├── app.py
│   ├── Dockerfile
│   └── requirements.txt
└── patched-app/        # Fixed version
    ├── app.py
    ├── Dockerfile
    └── requirements.txt

References¶

https://discuss.elastic.co/t/kibana-8-19-22-9-4-7-9-5-4-security-update-esa-2026-187/390860

Generated by PoC Generator on 2026-10-08T03:00:04.602473425

Frequently asked questions¶

What is CVE-2026-102406?¶

CVE-2026-102406 is a High (8.8) vulnerability: Authorization Bypass Through User-Controlled Key (CWE-639) in Kibana could lead to…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-102406?¶

Run the detection-only PoC included with this entry against your Docker test lab to confirm whether a target is affected; pair it with your own IDS logging.

How do I block or mitigate CVE-2026-102406?¶

Upgrade to a fixed version per the vendor advisory; the NVD record lists the affected versions. Use the included PoC to verify your remediation.

For authorized security testing and research only. See the full source and NVD record.