Is CVE-2026-33709 actively exploited?

CVE-2026-33709 has no public evidence of in-the-wild exploitation as of 2026-04-22.

What is the CVSS score for CVE-2026-33709?

CVE-2026-33709 has a CVSS score of 5.1 (MEDIUM severity). Vector: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X.

How do I patch CVE-2026-33709?

Patch guidance is available from jupyter security advisories. CVEDatabase generates AI-assisted remediation guidance on demand for CVE-2026-33709.

CVE-2026-33709 - remediation guidance & executive summary

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.

CVSS Metrics

Vector: 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector: network
Complexity: low
Privileges: none
User Action: active
Confidentiality: undefined
Integrity: undefined
Availability: undefined
Weaknesses: CWE-601

Metadata

Primary Vendor: JUPYTER
Published: 4/3/2026
Last Modified: 4/22/2026
Source: NIST NVD
Note: Verify all details with official vendor sources before applying patches.

CVE-2026-33709

Description

CVSS Metrics

Metadata

Affected Products

Remediation Guidance

Executive Summary