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.
History

Fri, 06 Nov 2026 22:00:00 +0000

Type Values Removed Values Added
First Time appeared Bubka
Bubka 2fauth
Vendors & Products Bubka
Bubka 2fauth

Fri, 06 Nov 2026 20:30:00 +0000

Type Values Removed Values Added
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.
Title 2FAuth: Reverse Proxy Guard Auto-Creates Users With Admin Promotion From Unauthenticated Header Value
Weaknesses CWE-287
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}


cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published: 2026-11-06T20:20:27.407Z

Updated: 2026-11-06T20:20:27.407Z

Reserved: 2026-07-16T19:35:57.767Z

Link: CVE-2026-63438

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-11-06T21:17:09.770

Modified: 2026-11-06T21:17:09.770

Link: CVE-2026-63438

cve-icon Redhat

No data.