CVE-2026-71416

Headroom vulnerable to Cross-Site WebSocket Hijacking (CSWSH)

Published Sep 11, 2026 CVSS 3.1 · 8.8 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Github GHSA Github GHSA GHSA-h46j-26q3-rggf Headroom vulnerable to Cross-Site WebSocket Hijacking (CSWSH)
History
Type Values Removed Values Added
First Time appeared Headroom Labs
Headroom Labs headroom
Vendors & Products Headroom Labs
Headroom Labs headroom
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title Headroom vulnerable to Cross-Site WebSocket Hijacking (CSWSH)
Weaknesses CWE-1385
CWE-287
References
Metrics cvssV3_1

{'score': 8.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 11, 2026, 2:33 PM
Reserved
Aug 6, 2026, 4:28 PM
Status
Deferred
Published
Sep 11, 2026, 2:17 PM
Modified
Sep 30, 2026, 7:57 PM