Missing Authentication in OpenHands Landing Page

Executive Summary

CVE-2026-122236 is a vulnerability in OpenHands up to version 1.24.0 where the session API key is exposed in plaintext on the unauthenticated landing page. This key is injected into the HTML for local mode and serves as a master credential across multiple services. The frontend server and reverse proxy bind to all network interfaces, making them accessible to any host on the local network. An attacker can retrieve this key via a simple HTTP GET request and use it to execute arbitrary commands, access files, or retrieve stored credentials.

The vulnerability arises because the session key is exposed unnecessarily and the services bind to all interfaces instead of loopback addresses. The fix restricts binding to loopback interfaces and removes key injection when bound to non-loopback addresses.

Useful 0 Not Useful 0

Detection Guidance

Check if OpenHands is running on ports 3001 or 8000 by using commands like 'netstat -tulnp | grep -E ":3001|:8000"' or 'ss -tulnp | grep -E ":3001|:8000"'. Verify if these ports are bound to all interfaces (0.0.0.0 or ::) using 'curl http://localhost:3001' or 'curl http://localhost:8000' to inspect the landing page HTML for the presence of 'window.__AGENT_CANVAS_SESSION_API_KEY__' in the response.

• Use 'nmap -p 3001,8000 <your-ip>' to scan for open ports. If accessible, test for the session key by sending a GET request to 'http://<your-ip>:8000/' or 'http://<your-ip>:3001/' and checking the response for the session key.

Useful 0 Not Useful 0

Impact Analysis

If you are using OpenHands up to version 1.24.0, an attacker on the same local network can exploit this vulnerability to retrieve your session API key. With this key, they can execute arbitrary commands on your machine, read files, access global settings, retrieve stored credentials (including LLM and third-party service keys), and read all conversation history. The attack requires no authentication and can be performed with a single HTTP request.

Useful 0 Not Useful 0

Compliance Impact

This vulnerability could lead to unauthorized access to sensitive data, including stored credentials and conversation history, which may violate GDPR (data protection) and HIPAA (health information privacy) requirements. Unauthorized command execution could also result in data breaches or unauthorized system access, further compromising compliance.

Useful 0 Not Useful 0

Mitigation Strategies

Upgrade OpenHands to version 1.25.0 or later immediately. If upgrading is not possible, restrict network access to ports 3001 and 8000 by binding them to loopback (127.0.0.1) or using a firewall to block external access.

• Disable the OpenHands client if not in use. Avoid running OpenHands in local mode where session keys are injected into the landing page HTML. Review and revoke any exposed session keys if a compromise is suspected.

Useful 0 Not Useful 0