CVE-2026-64835 — FFmpeg versions 4.4 through 8.1.2 contain an out-of-bounds memory access vulnerability in…¶
Key facts
CVE-2026-64835 is a High (8.8) vulnerability: FFmpeg versions 4.4 through 8.1.2 contain an out-of-bounds memory access vulnerability in…. This entry ships a detection-only PoC and a Docker test lab.
| CVE | CVE-2026-64835 |
| Severity | High (8.8) |
| Detection / prevention | — |
| PoC | poc.py |
| Source | 2026/CVE-2026-64835/ |
Details¶
English | 한국어
Description¶
FFmpeg versions 4.4 through 8.1.2 contain an out-of-bounds memory access vulnerability in the ADX audio decoder within libavcodec/adxdec.c that allows attackers to trigger both out-of-bounds reads and writes by supplying a crafted ADX or AAX audio file with a mid-stream channel layout change. When AV_PKT_DATA_NEW_EXTRADATA side data is received mid-stream, the adx_decode_frame function re-parses the stream header but fails to update the internal channel state, causing subsequent decoding operations to access the prev[] state array using a stale channel count.
Vulnerability Details¶
| Property | Value |
|---|---|
| CVE ID | CVE-2026-64835 |
| 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-2026-64835/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-2026-64835
# 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://code.ffmpeg.org/FFmpeg/FFmpeg/commit/1836ef96846937a6cc2443698a693104f5c0b21e
- https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23659
- https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-memory-access-in-adx-audio-decoder
Generated by PoC Generator on 2026-08-11T21:12:41.755481562
Frequently asked questions¶
What is CVE-2026-64835?¶
CVE-2026-64835 is a High (8.8) vulnerability: FFmpeg versions 4.4 through 8.1.2 contain an out-of-bounds memory access vulnerability in…. This entry ships a detection-only PoC and a Docker test lab.
How do I detect CVE-2026-64835?¶
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-2026-64835?¶
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.