CVE-2026-85440 — MOOS core-moos through 10.4.0 contains a pre-authentication heap overflow vulnerability…¶
Key facts
CVE-2026-85440 is a Critical (9.8) vulnerability: MOOS core-moos through 10.4.0 contains a pre-authentication heap overflow vulnerability…. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-85440 |
| Severity | Critical (9.8) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-85440/ |
Details¶
English | 한국어
Description¶
MOOS core-moos through 10.4.0 contains a pre-authentication heap overflow vulnerability in MOOSCommPkt packet handling that allows remote attackers to write arbitrary data by declaring a negative packet length. Attackers can exploit the signed integer check in InflateTo() and negative size conversion in recv() to overflow a four-byte heap buffer during the HandShake phase before authentication.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-85440 |
| Type | RCE |
| CVSS Score | 9.8 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-85440/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-2026-85440
# 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/themoos/core-moos
- https://github.com/themoos/core-moos/blob/ec9c77c68fcbdef8f5e4c60fe243acd223433f0c/Core/libMOOS/Comms/MOOSCommPkt.cpp#L67
- https://github.com/themoos/core-moos/commit/96c49c5cdda6e07ee734a5324e8d25ba5a7f2d7a
- https://github.com/themoos/core-moos/pull/82
- https://www.vulncheck.com/advisories/moos-core-moos-through-10.4.0-moosdb-pre-authentication-heap-overflow-via-negative-packet-length
Generated by PoC Generator on 2026-09-07T08:56:15.237149083
Frequently asked questions¶
What is CVE-2026-85440?¶
CVE-2026-85440 is a Critical (9.8) vulnerability: MOOS core-moos through 10.4.0 contains a pre-authentication heap overflow vulnerability…. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-85440?¶
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-2026-85440?¶
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.