CVE-2026-33709

JupyterHub has an Open Redirect Vulnerability

MEDIUM
6.1
CVSS Score
Published: April 3, 2026 at 10:00 PM UTC
Updated: July 24, 2026 at 10:20 PM UTC
2 products affected across 2 vendorsJupyterhubJupyterhub

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Severity
MEDIUM6.1
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 5.4.4
Affected range stops below 5.4.4, so it looks safe — our inference, not a vendor statement
v < 5.4.4
Affected range stops below 5.4.4, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (2)

x_refsource_CONFIRMMitigationVendor Advisory
Source: cverecord
https://github.com/jupyterhub/jupyterhub/security/advisories/GHSA-3vff-hjqv-m7h8
x_refsource_MISCProduct
Source: cverecord
https://github.com/jupyterhub/jupyterhub/releases/tag/5.4.4

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
LOW
Integrity
LOW
Availability
NONE
Vector?

Quick Info

StatusANALYZED
CWE
CWE-601

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