Open Redirect Vulnerability in JupyterHub Software by Jupyter Project
CVE-2026-33709

5.1MEDIUM

Key Information:

Vendor

Jupyterhub

Status
Jupyterhub
Vendor
CVE Published:
3 April 2026

What is CVE-2026-33709?

A significant security flaw has been identified in JupyterHub, a multi-user server software for Jupyter notebooks. This open redirect vulnerability allows attackers to create misleading links that redirect users away from JupyterHub to arbitrary sites controlled by the attacker. Upon clicking the link, users are initially directed to the JupyterHub login page, which then erroneously forwards them to potentially harmful external websites. This issue has been resolved in version 5.4.4 of JupyterHub, highlighting the importance of timely updates to maintain security.

Affected Version(s)

jupyterhub < 5.4.4

References

https://github.com/jupyterhub/jupyterhub/security/advisor...
x_refsource_CONFIRM
https://github.com/jupyterhub/jupyterhub/releases/tag/5.4.4
x_refsource_MISC

CVSS V4

Score:
5.1
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
Unknown

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.