CVE-2026-33175CWE-287CWE-290

OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims

High · published April 3, 2026

CVSS v3.1
8.8
EPSS
1%
Percentile
50.0
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v3.1
8.8 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00640 · 50.0th percentile
Weaknesses
CWE-287 · Improper Authentication; CWE-290 · Authentication Bypass by Spoofing
Published
2026-04-03T21:56Z
EPSS history
Timeline
  • 03 APR 21:56Z
    OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims
    cvelistv5