CVE-2026-68579 — FreeRDP before 3.30.0 (<= 3.29.0) contains a heap-based buffer overflow in the Windows…¶
Key facts
CVE-2026-68579 is a Critical (9.6) vulnerability: FreeRDP before 3.30.0 (<= 3.29.0) contains a heap-based buffer overflow in the Windows…. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-68579 |
| Severity | Critical (9.6) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-68579/ |
Details¶
English | 한국어
Description¶
FreeRDP before 3.30.0 (<= 3.29.0) contains a heap-based buffer overflow in the Windows clipboard client's CliprdrStream_Read function (client/Windows/wf_cliprdr.c). When an OLE paste consumer (e.g. explorer.exe) calls IStream::Read with a fixed-size buffer of cb bytes, CliprdrStream_Read requests file contents from the RDP server and then copies the response into the caller's buffer using the server-supplied length (req_fsize) instead of cb. A malicious or compromised RDP server can return an oversized CB_FILECONTENTS_RESPONSE, causing an out-of-bounds write of attacker-controlled data into the paste consumer's heap buffer when a user pastes server-offered clipboard file contents.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-68579 |
| Type | RCE |
| CVSS Score | 9.6 |
Proof of Concept¶
Download¶
# Download PoC script
curl -O https://raw.githubusercontent.com/fankh/vulnerability-poc/main/2026/CVE-2026-68579/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-2026-68579
# 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/FreeRDP/FreeRDP/commit/5e8e987b469b60a3bafadf8f5afc40f91c09f458
- https://github.com/FreeRDP/FreeRDP/security/advisories/GHSA-m37j-jcr2-8gcc
- https://www.vulncheck.com/advisories/freerdp-before-heap-overflow-via-cliprdrstream-read
Generated by PoC Generator on 2026-08-02T23:16:48.74956863
Frequently asked questions¶
What is CVE-2026-68579?¶
CVE-2026-68579 is a Critical (9.6) vulnerability: FreeRDP before 3.30.0 (<= 3.29.0) contains a heap-based buffer overflow in the Windows…. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-68579?¶
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-2026-68579?¶
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.