= 4.0.0-RC1 before 4.18.3 contain a…¶

Key facts

CVE-2026-72781 is a High (8.8) vulnerability: Craft CMS versions >= 5.0.0-RC1 before 5.10.7 and >= 4.0.0-RC1 before 4.18.3 contain a…. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-72781
Severity	High (8.8)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-72781/

Details¶

English | 한국어

Description¶

Craft CMS versions >= 5.0.0-RC1 before 5.10.7 and >= 4.0.0-RC1 before 4.18.3 contain a remote code execution vulnerability in the Twig sandbox mechanism. Because Craft marks the ElementInterface as safe (via the AllowedInSandbox attribute) and the sandbox allowlisting extends to the entire class hierarchy (craft\base\Component up to yii\base\Component), an authenticated attacker with permission to access the control panel can render a malicious Twig template that abuses the yii\base\Component arbitrary function-call gadget to execute arbitrary code, even when the Twig sandbox is enabled via enableTwigSandbox().

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-72781
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-2026-72781/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-2026-72781

# 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/craftcms/cms/security/advisories/GHSA-f5wm-88jv-g5hx
https://www.vulncheck.com/advisories/craft-cms-rc1-before-remote-code-execution-via-twig-sandbox-escape

Generated by PoC Generator on 2026-08-11T23:16:45.07383477

Frequently asked questions¶

What is CVE-2026-72781?¶

CVE-2026-72781 is a High (8.8) vulnerability: Craft CMS versions >= 5.0.0-RC1 before 5.10.7 and >= 4.0.0-RC1 before 4.18.3 contain a…. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-72781?¶

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-2026-72781?¶

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.