# CVE-2026-107147: twofactor_gauthenticator plugin for Roundcube authentication bypass via header spoofing

Source: https://junglewise.ai/threats/cve-2026-107147-the-twofactor-gauthenticator-plugin-for-roundcube-is-vulnerable  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-27. Updated: 2026-10-27  
License: CC BY 4.0 with a link back

CVE-2026-107147 · Severity: info · Published 2026-10-27

The twofactor_gauthenticator plugin for Roundcube is a two-factor authentication add-on that verifies user identity before allowing email access. An attacker who has obtained a user's password can bypass the second authentication factor by forging network header information (Client-IP and X-Forwarded-For) to make the system think the login is coming from a trusted location. This allows unauthorized access to user email accounts.

Technologies: [Alexandregz Twofactor Gauthenticator](https://junglewise.ai/threats/technologies/twofactor-gauthenticator). Vendors: [Alexandregz](https://junglewise.ai/threats/vendors/alexandregz).

## Quick answers

**Is CVE-2026-107147 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-107147 being exploited in the wild.

**How severe is CVE-2026-107147?** Informational severity, published 27 October 2026.

**Which products and versions are affected?** Alexandregz Twofactor Gauthenticator before commit 4640889.

**Is there a fix for CVE-2026-107147?** Yes: fixed in commit 4640889. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-107147 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-107147?** Check whether you run Alexandregz Twofactor Gauthenticator at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in commit 4640889

## Technical details

The plugin fails to validate the Client-IP and X-Forwarded-For HTTP headers when checking whether a client IP address is whitelisted, allowing header spoofing to bypass 2FA. An attacker with valid credentials can craft requests with forged headers matching a whitelisted IP to skip the second authentication factor. The vulnerability was fixed in commit 4640889.

## Affected products

- alexandregz twofactor_gauthenticator before commit 4640889

## Timeline

- 2026-10-27: disclosed

## References

- [https://github.com/](https://github.com/)
- [https://cert.pl/en/posts/2026/10/CVE-2026-107145](https://cert.pl/en/posts/2026/10/CVE-2026-107145)

## Related threats

- [Roundcube twofactor_gauthenticator insufficient session expiration](https://junglewise.ai/threats/cve-2026-107146-the-twofactor-gauthenticator-plugin-for-roundcube-is-vulnerable)
- [twofactor_gauthenticator plugin for Roundcube brute-force bypass](https://junglewise.ai/threats/cve-2026-107145-the-twofactor-gauthenticator-plugin-for-roundcube-is-vulnerable)