CVE-2026-71981 — Cypht before 2.12.2 contains a PHP object injection vulnerability that allows…¶
Key facts
CVE-2026-71981 is a High (8.8) vulnerability: Cypht before 2.12.2 contains a PHP object injection vulnerability that allows…. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-71981 |
| Severity | High (8.8) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-71981/ |
Details¶
English | 한국어
Description¶
Cypht before 2.12.2 contains a PHP object injection vulnerability that allows authenticated attackers to execute arbitrary operating system commands by supplying a crafted PHP object graph in the back_query GET parameter of the logout handler. Attackers can pass a base64-encoded serialized payload through this parameter, which is decoded and passed directly to unserialize() without an allow-list, signature check, or type restriction, enabling gadget-chain exploitation to achieve remote code execution as the web server process.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-71981 |
| 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-2026-71981/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-2026-71981
# 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/cypht-org/cypht/commit/e4aa2f34e33f9328e8c93514cc3966fc3d99925e
- https://github.com/cypht-org/cypht/pull/2073
- https://github.com/cypht-org/cypht/releases/tag/v2.12.2
- https://www.vulncheck.com/advisories/cypht-php-object-injection-rce-via-back-query-parameter
Generated by PoC Generator on 2026-09-02T09:17:03.596035049
Frequently asked questions¶
What is CVE-2026-71981?¶
CVE-2026-71981 is a High (8.8) vulnerability: Cypht before 2.12.2 contains a PHP object injection vulnerability that allows…. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-71981?¶
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-2026-71981?¶
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.