Two-Factor Authentication Vulnerability in 2FAuth Web App by Bubka
CVE-2026-63439

9.8CRITICAL

Key Information:

Vendor

Bubka

Status
2fauth
Vendor
CVE Published:
6 November 2026

What is CVE-2026-63439?

The 2FAuth web application, designed for managing Two-Factor Authentication accounts, contains a vulnerability that allows remote clients to authenticate as existing users, including administrators. This occurs when the AUTHENTICATION_GUARD is set to reverse-proxy-guard and the application fails to validate if the incoming requests are from trusted proxies. A malicious actor could forge the identity header to gain access to sensitive 2FA secrets and perform account management functions. This vulnerability has been resolved in version 8.0.0.

Affected Version(s)

2FAuth < 8.0.0

References

https://github.com/Bubka/2FAuth/security/advisories/GHSA-...
x_refsource_CONFIRM
https://github.com/Bubka/2FAuth/commit/43873cbfba445926c7...
x_refsource_MISC
https://github.com/Bubka/2FAuth/releases/tag/v8.0.0
x_refsource_MISC

CVSS V3.1

Score:
9.8
Severity:
CRITICAL
Confidentiality:
High
Integrity:
High
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.