CRITICALCVSS v3.1 9.8Vulnerability

CVE-2026-63439

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.

Properties

Severity
CRITICAL
Nvd fetched at
2026-11-07T06:40:34.987550+00:00
Cvss score
9.8
Cvss severity
CRITICAL
Retrieved at
2026-11-07T06:41:39+00:00
Score
9.8
Last source
NVD
Cvss version
3.1
Cve id
CVE-2026-63439
Cvss vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
First seen by Signal
2026-11-06T22:31:10+00:00
Name
CVE-2026-63439
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Published at
2026-11-06T21:17:09.970
Last modified
2026-11-06T21:17:09.970

Related Entities (1)

HAS_WEAKNESS (1)

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CVE-2026-63439 (CVSS v3.1 9.8) — Ninja Signal Threat Intelligence | Ninja Signal