CVE-2026-81891 — elFinder is an open-source file manager for web, written in JavaScript using jQuery UI.¶
Key facts
CVE-2026-81891 is a High (8.1) 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-2026-81891 |
| Severity | High (8.1) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-81891/ |
Details¶
English | 한국어
Description¶
elFinder is an open-source file manager for web, written in JavaScript using jQuery UI. Prior to 2.1.70, checkExtractItems() in php/elFinderVolumeDriver.class.php calls mimetypeInternalDetect() without passing the result through mimeTypeNormalize(). Because the .phtml, .phar, .php5, and .php3 extensions are absent from mime.types, the staticMimeMap entries that map them to text/x-php are not applied, and allowPutMime() permits extraction even when uploadDeny blocks text/x-php. An attacker with ZIP upload permission can extract PHP-executable files into a web-accessible files/ directory and achieve remote code execution when the server executes those extensions. This issue is fixed in version 2.1.70.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-81891 |
| Type | RCE |
| CVSS Score | 8.1 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-81891/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-2026-81891
# 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/dd73e702820c146a192969800ee674ecdb208365
- https://github.com/Studio-42/elFinder/releases/tag/2.1.70
- https://github.com/Studio-42/elFinder/security/advisories/GHSA-gxmj-r5rf-ggwq
Generated by PoC Generator on 2026-09-02T19:24:33.796239243
Frequently asked questions¶
What is CVE-2026-81891?¶
CVE-2026-81891 is a High (8.1) 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-2026-81891?¶
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-2026-81891?¶
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.