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CVE-2026-73040 — Dockge validates a stack name only on the write path.

Key facts

CVE-2026-73040 is a High (8.8) vulnerability: Dockge validates a stack name only on the write path.. This entry ships a detection-only PoC and a Docker test lab.
CVE CVE-2026-73040
Severity High (8.8)
Detection / prevention —
PoC poc.py
Source 2026/CVE-2026-73040/

Details

English | 한국어

Description

Dockge validates a stack name only on the write path. In backend/stack.ts the allow-list check in validate(), which requires the name to match ^[a-z0-9_-]+$, is reached from save() alone, while the path getter returns path.join(this.server.stacksDir, this.name) and Stack.getStack builds path.join(server.stacksDir, stackName) with no check. The socket handlers in backend/agent-socket-handlers/docker-socket-handler.ts confirm the caller is logged in and that the name is a string, then pass it straight to Stack.getStack, so a name containing traversal sequences resolves outside the managed stacks directory. An authenticated user can therefore read the composeENV and composeYAML values of any directory the server process can reach, which discloses the secrets in that directory's .env or Compose file, and can invoke delete(), which runs docker compose down and then fsAsync.rm on the traversed path with recursive and force set, removing that directory. Disclosure is limited to files named .env or an accepted Compose filename, and deletion requires the target directory to hold a valid Compose file so that docker compose down exits successfully. Dockge commonly runs as root with access to the Docker socket, so the reachable set includes unrelated applications on the host. Instances configured with disableAuth, a supported option that logs the caller in as admin automatically, expose both operations without authentication.

Vulnerability Details

Property Value
CVE ID CVE-2026-73040
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-2026-73040/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-2026-73040

# 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/louislam/dockge
  • https://github.com/louislam/dockge/blob/1.5.0/backend/agent-socket-handlers/docker-socket-handler.ts#L43-L78
  • https://github.com/louislam/dockge/blob/1.5.0/backend/stack.ts#L155-L157
  • https://github.com/louislam/dockge/blob/1.5.0/backend/stack.ts#L218-L232
  • https://github.com/louislam/dockge/blob/1.5.0/backend/stack.ts#L377-L379
  • https://github.com/louislam/dockge/issues/994
  • https://www.vulncheck.com/advisories/dockge-path-traversal-via-unvalidated-stack-name-allows-arbitrary-compose-and-env-disclosure-and-arbitrary-directory-deletion
  • https://github.com/louislam/dockge/issues/994

Generated by PoC Generator on 2026-08-22T22:14:46.280220615

Frequently asked questions

What is CVE-2026-73040?

CVE-2026-73040 is a High (8.8) vulnerability: Dockge validates a stack name only on the write path.. This entry ships a detection-only PoC and a Docker test lab.

How do I detect CVE-2026-73040?

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-2026-73040?

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.