CVE-2026-63438
Received Received - Intake

Remote User Authentication Bypass in 2FAuth

Vulnerability report for CVE-2026-63438, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.

Publication date: 2026-11-06

Last updated on: 2026-11-06

Assigner: GitHub, Inc.

Description

2FAuth is a web app to manage Two-Factor Authentication (2FA) accounts and generate their security codes. Prior to 8.0.0, when AUTHENTICATION_GUARD=reverse-proxy-guard accepts authentication headers from a client that did not pass through a trusted proxy, RemoteUserProvider::retrieveById() creates an account for an unknown REMOTE_USER, promotes the first created account to administrator, and synchronizes the account email from the configured mail header. An unauthenticated remote client can therefore create an administrator on a fresh instance or impersonate and redirect email for a known account, exposing 2FA secrets and administrative functions. This issue is fixed in version 8.0.0.

CVSS Scores

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Meta Information

Published
2026-11-06
Last Modified
2026-11-06
Generated
2026-11-06
EPSS Evaluated
N/A
NVD
EUVD

Affected Vendors & Products

Currently, no data is known.

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-287 When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.

Attack-Flow Graph

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