CVE-2026-33709
MediumCVSS 6.1Exploitation Probability (EPSS)
Low risk13th percentile - higher than 13% of all known CVEs
Summary
JupyterHub before version 5.4.4 has an open redirect vulnerability that 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, bypassing JupyterHub's check to prevent this.
Risk Assessment
An attacker can use this for phishing, redirecting users after login to a malicious site, potentially leading to theft of login credentials or other sensitive information.
Recommendation
Update JupyterHub to version 5.4.4, which contains the fix.
Original NVD description (English source)
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.