CVE-2026-63439: 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. Until upgrading, do not enable AUTHENTICATION_GUARD=reverse-proxy-guard unless the application is strictly protected behind a trusted reverse proxy that enforces identity headers. Verify that only trusted proxies can send identity headers to prevent header forgery.
Description
CVE-2026-63439 is a critical improper authentication vulnerability in Bubka 2FAuth versions prior to 8.0.0. When the AUTHENTICATION_GUARD is set to reverse-proxy-guard, the application trusts the REMOTE_USER identity header or a custom header without verifying the request's origin from a trusted proxy. This allows remote attackers who can access the application directly to forge identity headers and authenticate as any user, including administrators, potentially exposing stored 2FA secrets and management functions. The issue is fixed in version 8.0.0.