CVE-2026-63438: Bubka 2FAuth · Improper Authentication
Affects Bubka 2FAuthSource CVE Database V5
Not known to be exploited · CVSS 9.8 Critical : upgrade to 8.0.0 as a priority.
Data as of 6 Nov 2026, 21:02 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 9.8 |
|---|
- Patch
- Available – fixed in 8.0.0
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 6 Nov 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade 2FAuth and bubka/2FAuth to 8.0.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Bubka2FAuth | Affected
| Fixed in
|
GitHubbubka/2FAuthpkg:github/bubka/2FAuthOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Upgrade Bubka 2FAuth to version 8.0.0 or later, where this improper authentication vulnerability is fixed. No other mitigations are indicated by the vendor advisory. Users should apply this official fix promptly to prevent unauthorized administrative access and exposure of 2FA secrets.
Description
CVE-2026-63438 is a critical improper authentication vulnerability in Bubka's 2FAuth web application prior to version 8.0.0. When configured with AUTHENTICATION_GUARD=reverse-proxy-guard, the application incorrectly accepts authentication headers from clients not passing through a trusted proxy. This flaw allows unauthenticated remote clients to create administrator accounts on fresh instances or impersonate existing users by synchronizing email headers, exposing two-factor authentication secrets and administrative functions. The issue is resolved in version 8.0.0.
References
- github.com/Bubka/2FAuth/security/advisories/GHSA-r9xx-45m8-mw24 (opens in a new tab)
- github.com/Bubka/2FAuth/commit/43873cbfba445926c7008b4291eeee67752af9e8 (opens in a new tab)
- github.com/Bubka/2FAuth/commit/8a4c395cac97f8b70b4a822639a6ad8a816f927c (opens in a new tab)
- github.com/Bubka/2FAuth/commit/d9e58ac4a63fbd8a073e423567881c81a87915de (opens in a new tab)
- github.com/Bubka/2FAuth/releases/tag/v8.0.0 (opens in a new tab)