๐Ÿ” CVE Alert

CVE-2026-63439

CRITICAL 9.8

2FAuth: Reverse Proxy Guard Trusts Client-Supplied Headers Without Proxy Verification

CVSS Score
9.8
EPSS Score
0.0%
EPSS Percentile
0th

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 is enabled, ReverseProxyGuard::user() reads the default REMOTE_USER identity header, or a custom identity header selected by the AUTH_PROXY_HEADER_FOR_USER configuration setting, without confirming that the request originated from a configured trusted proxy. A remote client that can reach the application directly can forge the selected identity header and authenticate as an existing user, including an administrator, gaining access to stored 2FA secrets and account or application management functions. This issue is fixed in version 8.0.0.

CWE CWE-287
Vendor bubka
Product 2fauth
Published Nov 6, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

Affected Versions

Bubka / 2FAuth
< 8.0.0

References

NVD โ†— CVE.org โ†— EPSS Data โ†—
github.com: https://github.com/Bubka/2FAuth/security/advisories/GHSA-mh8r-74x2-r457 github.com: https://github.com/Bubka/2FAuth/commit/43873cbfba445926c7008b4291eeee67752af9e8 github.com: https://github.com/Bubka/2FAuth/releases/tag/v8.0.0