CVE-2026-19513 — The Gravity Forms plugin for WordPress is vulnerable to Arbitrary File Upload in all…¶
Key facts
CVE-2026-19513 is a High (8.1) vulnerability: The Gravity Forms plugin for WordPress is vulnerable to Arbitrary File Upload in all…. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-19513 |
| Severity | High (8.1) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-19513/ |
Details¶
English | 한국어
Description¶
The Gravity Forms plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 3.0.2. This is due to insufficient validation of multi-file upload chunk state in the GFAsyncUpload::upload() function, where public form state URL hashes can be reused as chunk continuation hashes and attacker-controlled temporary filenames are accepted before sanitization. This makes it possible for unauthenticated attackers, when a public form contains a File Upload field with Multiple Files enabled, to upload a valid PNG/PDF polyglot to an attacker-selected public .php or .html filename in the Gravity Forms temporary upload directory. This can lead to remote code execution on WordPress systems that use NGINX or other non .htaccess respecting web servers. NOTE: During installation and activation, the Gravity Forms plugin places a .htaccess file in this directory, which prevents this vulnerability from being exploited despite the PHP file being written to the temporary upload directory. In these cases where PHP execution is blocked, attacker-written HTML can result in stored same-origin cross-site scripting if a victim visits the generated file URL.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-19513 |
| Type | XSS |
| CVSS Score | 8.1 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-19513/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-2026-19513
# 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://docs.gravityforms.com/gravityforms-change-log/
- https://www.wordfence.com/threat-intel/vulnerabilities/id/d20b2d00-054e-4772-a5a5-b7b33063043c?source=cve
Generated by PoC Generator on 2026-09-02T15:06:55.0345243
Frequently asked questions¶
What is CVE-2026-19513?¶
CVE-2026-19513 is a High (8.1) vulnerability: The Gravity Forms plugin for WordPress is vulnerable to Arbitrary File Upload in all…. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-19513?¶
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-2026-19513?¶
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.