CVE-2026-71416: Headroomlabs-Ai Headroom

High severity, CVSS 8.8. EPSS: 0.2% chance of exploitation in the next 30 days.

Headroom compresses data before the data reaches a large language model. Prior to version 0.35.0, the Headroom WebSocket server does not validate the `Origin` header of incoming client WebSocket requests before forwarding the request to the upstream server, allowing malicious WebSocket clients to perform arbitrary LLM requests without authentication. This can be exploited by a malicious WebSocket client executed in a traditional or headless browser such as lightpanda, if the browser has access to the Headroom proxy and the OpenAI API key is stored in the `OPENAI_API_KEY` environment variable. Version 0.35.0 fixes the issue.

Affected products

• Headroomlabs-Ai Headroom: before 0.35.0 (fixed in 0.35.0)

Published 2026-09-11. Last modified 2026-09-30.