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TI-2026-81071 Aliases CVE-2026-107147GHSA-f37x-h4hh-7q49

Authentication bypass by spoofing in twofactor_gauthenticator

Priority LOW 28CWE-290Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Attack requirements
None
Impact type
Security bypass
Confidentiality · integrity · availability
Low · Low · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-290.

Summary

The twofactor_gauthenticator plugin for Roundcube lets an attacker bypass its second factor. The plugin does not validate the Client-IP and X-Forwarded-For headers, so an attacker who obtains a user's password can spoof a whitelisted IP address and skip the second factor. This is tracked as CWE-290, Authentication Bypass by Spoofing.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Description from the CNA

The twofactor_gauthenticator plugin for Roundcube is vulnerable to 2fa authentication bypass by spoofed client address headers. Due to the lack of validation of the Client-IP and X-Forwarded-For headers, an attacker who obtains user's password can spoof a whitelisted IP address, resulting in the second factor being bypassed. This issue was fixed in commit 4640889.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00392 33rd percentileScored 2026-11-07
Fix Fixed No fixed version in the sources yet

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

No affected products listed by the sources yet.

Remediation

Update alexandregz twofactor_gauthenticator to commit 4640889, which fixes the issue.

Written with Claude Haiku 5.5 from the sources below · 2026-11-04

Fixed in the same release

Records fixed by the same vendor advisory or release, as the CNA lists them.

  • Release ·

    alexandregz twofactor_gauthenticator 4640889

    3 records Highest priority Priority LOW 3 LOW

    Other records, highest priority first

    • TI-2026-81070 Session stays alive after failed 2FA in twofactor_gauthenticatorPriority LOW 28
    • TI-2026-81069 Missing rate limiting in Roundcube twofactor_gauthenticator 2FA checksPriority LOW 28
    Show all 3 records →

Timeline

  1. 2026-10-27 Threatist record created from CVE-2026-107147
  2. 2026-10-27 Alias added: GHSA-f37x-h4hh-7q49
  3. 2026-10-27 Priority changed: MEDIUM → LOW
  4. 2026-11-04 CISA SSVC decision points changed

References

Patch 1

Advisory 1

  • TI-2026-81070 Session stays alive after failed 2FA in twofactor_gauthenticator CVSS 4.0MEDIUM 6.3
  • TI-2026-81069 Missing rate limiting in Roundcube twofactor_gauthenticator 2FA checks CVSS 4.0MEDIUM 6.3

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences