CVE-2026-70553 — MaxSite CMS contains a remote code execution vulnerability that allows unauthenticated…¶
Key facts
CVE-2026-70553 is a Critical (9.8) vulnerability: MaxSite CMS contains a remote code execution vulnerability that allows unauthenticated…. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-70553 |
| Severity | Critical (9.8) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-70553/ |
Details¶
English | 한국어
Description¶
MaxSite CMS contains a remote code execution vulnerability that allows unauthenticated attackers to inject arbitrary PHP code into the application configuration file by submitting crafted POST requests to the install endpoint after installation is complete. Attackers can supply a malicious db_dbprefix value containing a single quote to break out of a PHP string literal in application/config/database.php, appending attacker-controlled PHP statements that are executed by the web server on every subsequent request, resulting in persistent unauthenticated remote code execution as the web-server process user.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-70553 |
| Type | RCE |
| CVSS Score | 9.8 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-70553/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-2026-70553
# 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://github.com/maxsite/cms
- https://max-3000.com/page/maxsite-cms-109-6
- https://www.vulncheck.com/advisories/maxsite-cms-unauthenticated-rce-via-install-endpoint
Generated by PoC Generator on 2026-08-10T09:22:34.805316447
Frequently asked questions¶
What is CVE-2026-70553?¶
CVE-2026-70553 is a Critical (9.8) vulnerability: MaxSite CMS contains a remote code execution vulnerability that allows unauthenticated…. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-70553?¶
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-2026-70553?¶
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.