CVE-2026-33175

OAuthenticator: Authentication Bypass in Auth0OAuthenticator via Unverified Email Claims

HIGH
8.8
CVSS Score
Published: April 3, 2026 at 09:56 PM UTC
Updated: July 24, 2026 at 10:20 PM UTC
2 products affected across 2 vendorsOauthenticatorOauthenticator

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Severity
HIGH8.8
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

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.

Affected

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

v < 17.4.0
Affected range stops below 17.4.0, so it looks safe — our inference, not a vendor statement
v < 17.4.0
Affected range stops below 17.4.0, 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:

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

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

CVSS

8.8HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-287CWE-290

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