CVE-2026-33709
Open Redirect Vulnerability in JupyterHub Allows Phishing Redirects
Publication date: 2026-04-03
Last updated on: 2026-04-22
Assigner: GitHub, Inc.
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| jupyter | jupyterhub | to 5.4.4 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-601 | The web application accepts a user-controlled input that specifies a link to an external site, and uses that link in a redirect. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability is an open redirect issue in JupyterHub versions prior to 5.4.4. It allows attackers to create specially crafted links that, when clicked, first take users to the JupyterHub login page and then redirect them to an arbitrary attacker-controlled website outside of JupyterHub. This bypasses JupyterHub's normal checks designed to prevent such redirects.
How can this vulnerability impact me? :
The vulnerability can be exploited by attackers to redirect users to malicious websites after they attempt to log in to JupyterHub. This could lead to phishing attacks, where users are tricked into providing sensitive information or downloading malicious content, potentially compromising user security and trust.
What immediate steps should I take to mitigate this vulnerability?
To mitigate this vulnerability, you should upgrade JupyterHub to version 5.4.4 or later, where the open redirect issue has been patched.