CVE-2026-33175 | BDVDB-2026-324682 Detail

jupyterhuboauthenticator

Description#

OAuthenticator is software that allows OAuth2 identity providers to be plugged in and used with JupyterHub. Prior to version 17.4.0, an authentication bypass vulnerability in oauthenticator allows an attacker with an unverified email address on an Auth0 tenant to login to JupyterHub. When email is used as the usrname_claim, this gives users control over their username and the possibility of account takeover. This issue has been patched in version 17.4.0.

Impact#

Per CVSS v3.1: confidentiality impact high, integrity impact high, availability impact high. Attack vector: network.

Weaknesses#

CWE-287 Improper Authentication
CWE-290 Authentication Bypass by Spoofing

References#

Exploit#

No public exploit known

History#

Version 12026-04-03Record published in the CVE List.
Version 22026-04-07Most recent update recorded in the CVE List.

Published

Published: 2026-04-03
Last modified: 2026-04-07

Vendor information

Vendor: jupyterhub
Product: oauthenticator

All jupyterhub vulnerabilities

Score

8.8 High

EPSS

less than 1%, Very Low

Estimated chance of exploitation in the next 30 days. EPSS percentile: 39.0.

KEV

Not listed in the CISA Known Exploited Vulnerabilities catalog.

Impact

Authentication Issues

Action

No specific action is recorded in the source data. Check the references for vendor guidance.

Affected Systems

Vulnerable
< 17.4.0
Fixed
Not stated

Scoring System

CVSS v4.0

Not available

CVSS v3.1

8.8 High

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

Metric breakdown
Attack Vector	Network
Attack Complexity	Low
Privileges Required	Low
User Interaction	None
Scope	Unchanged
Confidentiality	High
Integrity	High
Availability	High

CVSS v3.0

Not available

CVSS v2

Not available

Source: CVE List v5 (record); CISA KEV (kev, action); FIRST EPSS (epss).