CVE-2026-33709
JupyterHub has an Open Redirect Vulnerability
6.1
MEDIUM
CVSS 3.1
EPSS 0.01%
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.
How to fix CVE-2026-33709
To remediate CVE-2026-33709, upgrade the affected package to a fixed version below.
- —upgrade to 5.4.4 or later
- —no fix listed
- —upgrade to 5.4.4 or later
Is CVE-2026-33709 being exploited?
Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.
Affected packages (3)
- from 0, < 5.4.4
- from 0
- from 0, < 5.4.4
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N |
| osv | CVSS 3.1 | MEDIUM6.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N |