Headroom vulnerable to Cross-Site WebSocket Hijacking (CSWSH)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.8 · CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

EPSS

• CVE-2026-71416: 0.17% estimated exploitation activity in the next 30 days; percentile 6.85 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary 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 OPENAIAPIKEY environment variable. Details The Headroom server defines a WebSocket handler at ws://<headroomhost:8787/v1/responses in headroom/providers/proxyroutes.py: In the handleopenairesponsesws() method of the OpenAIHandlerMixin class, the Origin header of the WebSocket client handshake is not checked or verified before calling websocket.accept(), which grants any WebSocket client (including malicious clients) access to the server: The malicious WebSocket client does not need to provide authentication headers or API…

Published by the source

2 Oct 2026, 23:09 UTC

Last modified by the source

15 Oct 2026, 14:55 UTC

Source last checked

26 Oct 2026, 13:54 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-h46j-26q3-rggf

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-h46j-26q3-rggf

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-h46j-26q3-rggf

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# Patch Next advisory brief: CVE-2026-71416

Advisory: Headroom vulnerable to Cross-Site WebSocket Hijacking (CSWSH)
IDs: CVE-2026-71416, GHSA-h46j-26q3-rggf
Record: https://patchnext.com/advisories/cve-2026-71416 (revision 3, source checked 26 Oct 2026, 13:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: headroom-ai 0.35.0. A vendor fix does not mean a deployment is fixed.

## Affected components
- PyPI headroom-ai: affected < 0.35.0; fixed in 0.35.0

## Suggested inspection (read-only)
- `python -m pip show headroom-ai`: prints the installed version. Run with the environment that serves production active.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on headroom-ai.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-h46j-26q3-rggf (GitHub-reviewed advisory GHSA-h46j-26q3-rggf lists affected ranges: PyPI headroom-ai >=0 <0.35.0)
- Verified: https://osv.dev/vulnerability/GHSA-h46j-26q3-rggf (OSV record GHSA-h46j-26q3-rggf lists affected ranges: PyPI headroom-ai >=0 <0.35.0 (fixed))

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