JupyterHub has an Open Redirect Vulnerability

MEDIO 6.1CVE-2026-33709 · BIT-jupyterhub-2026-33709 · GHSA-3vff-hjqv-m7h8 · Published 03/04/2026 · updated 24/07/2026

In breve

CVE-2026-33709 è una vulnerabilità MEDIO (CVSS 6.1) che riguarda jupyterhub, jupyterhub (jupyter).
Probabilità di sfruttamento nei prossimi 30 giorni (EPSS): 0.21%, superiore al 11.8% delle vulnerabilità.
Correzione: aggiornare a 5.4.4 o successiva.

Package	Affected versions	Patched versions
jupyterhub PyPI	`< 5.4.4`	`5.4.4`
jupyterhub jupyter	`< 5.4.4`	`5.4.4`

Description

Affected Version

JupyterHub <= 5.4.3

Impact

An open redirect vulnerability in JupyterHub <=5.4.3 allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this.

Patches

Upgrade to JupyterHub 5.4.4

Workarounds

A deployment can apply filters on the Location header in a reverse proxy such as nginx/apache/traefik.

NVD description

JupyterHub is software that allows one to create a multi-user server for Jupyter notebooks. Prior to version 5.4.4, an open redirect vulnerability in JupyterHub allows attackers to construct links which, when clicked, take users to the JupyterHub login page, after which they are sent to an arbitrary attacker-controlled site outside JupyterHub instead of a JupyterHub page, bypassing JupyterHub's check to prevent this. This issue has been patched in version 5.4.4.