---
id: "CVE-2026-107145"
kind: "vulnerability"
aliases: ["CVE-2026-107145"]
title: "Roundcube 2FA plugin lacks rate limiting, allowing second-factor brute force"
severity: "medium"
cvss: 6.3
epss: null
exploited: false
status: "open"
category: "package"
products: []
ecosystems: []
tags: ["email", "mail-server", "package", "roundcube", "self-hosted"]
not_affected_if: ["2fa-not-enabled", "plugin-not-installed"]
published_at: "2026-10-27T10:16:54+00:00"
first_seen_at: "2026-10-27T10:31:02+00:00"
updated_at: "2026-10-27T10:32:00+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-107145", "first_seen_at": "2026-10-27T10:31:02+00:00"}]
---

# Roundcube 2FA plugin lacks rate limiting, allowing second-factor brute force

The twofactor_gauthenticator plugin for Roundcube does not rate-limit attempts at the second-factor code. An attacker who already has a user's password can try arbitrary 6-digit codes until one works and gets into the mailbox.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- Check whether the `twofactor_gauthenticator` plugin is installed in the Roundcube `plugins/` directory or the `config/config.inc.php` plugin list
- Check the installed plugin version against the fixed commit `4640889`, which the sources do not map to a release number: unknown

## Fix

- Update the `twofactor_gauthenticator` plugin to a build that includes commit `4640889`; the release version is unknown
- Until updated, disable the plugin or enforce a stronger second factor for Roundcube logins

## Timeline

- 2026-10-27T10:31:02+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-107145

## From the sources

The twofactor_gauthenticator plugin for Roundcube is vulnerable to brute-forcing of the second-factor code. Due to the lack of rate limiting, an attacker who obtains user's password can submit arbitrary 6-digit codes, resulting in second-factor bypass and unauthorized access to the system.




This issue was fixed in commit 4640889.

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