CVE-2026-33709

EUVD-2026-18880

03.04.2026, 22:16

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.

Open Redirect

Provider	Type	Base Score	Atk. Vector	Atk. Complexity	Priv. Required	Vector
NIST	Primary	UNKNOWN				---

Awaiting analysis

This vulnerability is currently awaiting analysis.

Base Score

CVSS 3.x

EPSS Score

Percentile: Unknown

Debian Releases

Debian Product

Codename

jupyterhub

bookworm	vulnerable
forky	vulnerable
sid	vulnerable
trixie	vulnerable

Common Weakness Enumeration

CWE-601 - URL Redirection to Untrusted Site ('Open Redirect')
A web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a Redirect. This simplifies phishing attacks.

References

https://github.com/jupyterhub/jupyterhub/releases/tag/5.4.4

https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-3vff-hjqv-m7h8