Is CVE-2026-33709 in the CISA KEV catalog?

No. CVE-2026-33709 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2026-33709?

CVE-2026-33709 has a CVSS v3 base score of 6.1 (MEDIUM).

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

CVE-2026-33709 has an EPSS score of 0.22% (13th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2026-33709?

Upgrade jupyterhub to 5.4.4 or later.

CVE & CISA-KEV Catalog

CVE-2026-33709

MEDIUM

6.1

CVSS v3

NVD

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.

CWE-601Open Redirect

How to fix

Remediation Available

jupyterhubNVD

Affected:< 5.4.4Fixed in:5.4.4CVE-2026-33709derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionRequired

ScopeChanged

Impact

ConfidentialityLow

IntegrityLow

AvailabilityNone

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Exploit Intelligence

0.22%probability of exploitation in 30 days

13thpercentile

Low risk: more likely to be exploited than 13% of all known CVEs.

References

Vendor Advisory1

github.com

Product1

github.com

Related Vulnerabilities

Other CWE-601 (Open Redirect) vulnerabilities, ordered by exploit likelihood. View all

CVE	Severity	CVSS	EPSS	Exploited	Fix
CVE-2025-4123	High	7.6	98%	-	Fix
CVE-2018-11784	Medium	4.3	94%	-	Fix
CVE-2021-22881	Medium	6.1	87%	-	Fix
CVE-2022-45402	Medium	6.1	82%	-	Fix
CVE-2017-1000117	High	8.8	78%	-	Fix
CVE-2019-10098	Medium	6.1	74%	-	Fix

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2026-04-22.