Vulnerability · Published Sep 11, 2026 · Assigned by GitHub_M

CVE-2026-71416Headroom vulnerable to Cross-Site WebSocket Hijacking (CSWSH)

High 8.8

In plain English

A high-severity improper authentication in headroom from headroomlabs-ai. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 7% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.2%top 93.1% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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 packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	headroom-ai	0.35.0	GHSA-h46j-26q3-rggf
PyPI	headroom-ai	0.35.0	PYSEC-2026-4220

Affected products (as reported)

Vendor	Product	Versions
headroomlabs-ai	headroom	< 0.35.0

Weakness: CWE-287, CWE-1385 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References

https://github.com/headroomlabs-ai/headroom/security/advisories/GHSA-h46j-26q3-rggf x_refsource_CONFIRM
https://github.com/headroomlabs-ai/headroom/releases/tag/v0.35.0 x_refsource_MISC