CVE-2026-81889 — elFinder is an open-source file manager for web, written in JavaScript using jQuery UI.¶

Key facts

CVE-2026-81889 is a High (8.6) vulnerability: elFinder is an open-source file manager for web, written in JavaScript using jQuery UI.. This entry ships a detection-only PoC and a Docker test lab.


CVE	CVE-2026-81889
Severity	High (8.6)
Detection / prevention	—
PoC	poc.py
Source	2026/CVE-2026-81889/

Details¶

English | 한국어

Description¶

elFinder is an open-source file manager for web, written in JavaScript using jQuery UI. Prior to 2.1.70, elFinder URL uploads in php/elFinder.class.php can bypass server-side request forgery protections when PHP cURL is unavailable because validate_address() validates $info['ip'], but get_remote_contents() selects fsock_get_contents(), which connects to $arr['host'] and performs a second DNS resolution. An attacker able to submit a URL upload can use DNS rebinding to have the first resolution return a public address and the connection resolution return a loopback or private address, causing the internal HTTP response body to be stored as an uploaded file and made readable through elFinder. After a successful fetch, get_headers($url, true) separately requests the original hostname without reusing the validated and pinned connection, creating an additional blind server-side request forgery path even when curl_get_contents() is selected. This issue is fixed in version 2.1.70.

Vulnerability Details¶

Property	Value
CVE ID	CVE-2026-81889
Type	SSRF
CVSS Score	8.6

Proof of Concept¶

Download¶

# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-81889/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-2026-81889

# 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/Studio-42/elFinder/commit/191372c1bbebbd36fb55af79a84b9984861390ff
https://github.com/Studio-42/elFinder/commit/6d997386cd0f1abab4706c220b46b0aea0ecff51
https://github.com/Studio-42/elFinder/releases/tag/2.1.70
https://github.com/Studio-42/elFinder/security/advisories/GHSA-8x3q-jpjh-qh5c

Generated by PoC Generator on 2026-09-02T19:41:15.234228934

Frequently asked questions¶

What is CVE-2026-81889?¶

CVE-2026-81889 is a High (8.6) vulnerability: elFinder is an open-source file manager for web, written in JavaScript using jQuery UI.. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-81889?¶

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-2026-81889?¶

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.