CVE-2024-28179: Jupyter Server Proxy's Websocket Proxying does not require authentication

Severity: critical (CVSS 9.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-03-20 · updated 2026-06-17
Weakness: CWE-306

Description

Jupyter Server Proxy allows users to run arbitrary external processes alongside their Jupyter notebook servers and provides authenticated web access. Prior to versions 3.2.3 and 4.1.1, Jupyter Server Proxy did not check user authentication appropriately when proxying websockets, allowing unauthenticated access to anyone who had network access to the Jupyter server endpoint. This vulnerability can allow unauthenticated remote access to any websocket endpoint set up to be accessible via Jupyter Server Proxy. In many cases, this leads to remote unauthenticated arbitrary code execution, due to how affected instances use websockets. The websocket endpoints exposed by `jupyter_server` itself is not affected. Projects that do not rely on websockets are also not affected. Versions 3.2.3 and 4.1.1 contain a fix for this issue.

Affected products

jupyterhub jupyter-server-proxy: before 3.2.3; from 4.0.0 before 4.1.1 — fixed in 3.2.3, 4.1.1

How to fix

Upgrade to a fixed version: jupyterhub jupyter-server-proxy 3.2.3, 4.1.1. Check the vendor advisory for mitigations.

References

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